小技巧
如果只是略微超过long long范围，可以使用__int128
__int128目前已知可以使用
-
<比较大小
-
四则运算
-
取模
高精度
介绍:
我们有些时候要对很大的数(超出long long范围)进行加减乘除,普通的运算符无法完成,我们就需要使用高精度
代码
C++
#include
using namespace std;//请将函数复制在你的程序里,不用直接从本文件调用!)
C++
//前置（定义变量）（将此代码复制在主函数外）
string sa, sb;
int la, lb, lc;
int a[99999], b[99999], c[99999];
//前置（输入并处理）（放在运算函数的前面）
cin >> sa >> sb;
la = sa.size();
lb = sb.size();
lc = max(la, lb);
for (int i = 0; i < la; i++)
a[la - i] = sa[i] - '0';
for (int i = 0; i < lb; i++)
b[lb - i] = sb[i] - '0';
//输出结果的代码
for (int i = lc; i > 0; i--)
cout << c[i];大数加法
//参数(加数,加数,进制(<=10))
C++
void add(int B) {
for (int i = 0; i <= lc; i++) //先加
c[i] = a[i] + b[i];
for (int i = 0; i <= lc; i++) { //进位
c[i + 1] += c[i] / B;
c[i] %= B;
}
if (c[lc + 1] != 0)
lc++;
while (c[lc] == 0 && lc > 1)
lc--;//去前导0
}大数减法
C++
void sub() {
for (int i = 0; i <= lc; i++)
c[i] = a[i] - b[i];
for (int i = 0; i <= lc; i++) {
if (c[i] < 0) {
c[i] += 10;
c[i + 1]--;
}
}
while (c[lc] == 0 && lc > 1)
lc--;
}大数乘法
高精度乘低精度
C++
void mul_small(int x) {
for (int i = 0; i <= lc; i++) //先加
c[i] = a[i] * x;
for (int i = 0; i <= lc; i++) { //进位
c[i + 1] += c[i] / 10;
c[i] %= 10;
}
if (c[lc + 1] != 0)
lc++;
while (c[lc] == 0 && lc > 1)
lc--;//去前导0
}高精度乘高精度
C++
string s1, s2;
string mul() {
int n1 = s1.size(), n2 = s2.size();
string res(n1 + n2, '0');
for (int i = n1 - 1; i >= 0; i--) {
for (int j = n2 - 1; j >= 0; j--) {
int t = res[i + j + 1] - '0' + (s1[i] - '0') * (s2[j] - '0'); //加本位
res[i + j] += t / 10;
res[i + j + 1] = t % 10 + '0';
}
}
for (int i = 0; i < n1 + n2; i++)
if (res[i] != '0')
return res.substr(i);
return "0";
}
int main() {
cin >> s1 >> s2;
cout << mul() << endl;
return 0;
}高精乘高精的压位高精度乘法（23.10.7）
C++
/*ACACACACACACAC///
. Code by Ntsc .
. Earn knowledge .
/*ACACACACACACAC///
#include<bits/stdc++.h>
#define int long long
#define db double
#define rtn return
using namespace std;
const int N=1e5+5;
const int M=1e5;
const int Mod=1e5;
const int INF=1e5;
int n,m,p,q,T;
string sa,sb;
struct node{
int res[N];//define为ll ，压8位
int len;
};
node mul(node a,node b){
node c;
int n=a.len,m=b.len;
for(int i=1;i<=n;i++){
for(int j=1;j<=m;j++){
c.res[i+j-1]+=a.res[i]*b.res[j];
}
}
for(int i=1;i<=n+m-1;i++){
c.res[i+1]+=c.res[i]/100000000;
c.res[i]%=100000000;
}
c.len=n+m-1;
while(c.res[c.len+1])c.len++;
return c;
}
node init(string s){//字符串转压位数组
node a;
a.len=0;
int l=s.size();
int t=0;
for(int i=l-1,k=0;i>=0;i--){
k++;
t+=(s[i]-'0')*pow(10,k-1);
if(k==8||i==0){
a.res[++a.len]=t;
t=0;k=0;
}
}
return a;
}
inline void out(node a){//请开栈！ //输出压位数组
cerr<<a.len<<endl;
printf("%lld",a.res[a.len]);
for(int i=a.len-1;i;i--)printf("%08lld",a.res[i]);
}
signed main(){
cin>>sa>>sb;
node a=init(sa);
node b=init(sb);
node c=mul(a,b);
out(c);
return 0;
}补充知识：printf固定前缀0输出
C++
int a = 4;
printf("%03d",a);输出：004
也可以用 * 代替位数，在后面的参数列表中用变量控制输出位数；
C++
int a = 4;
int n = 3;
printf("%0*d",n,a);输出：004
大数除法(大数/单精度)
C++
void div_small(int x) {
lc = la;
for (int i = 0; i < lc; i++) {
c[i] = a[i] / x;
a[i + 1] += (a[i] % x) * 10;
}
c[lc] = a[lc] / x;
int yu = a[lc] % x;
}
C++
string divv(string a,int b){
// int b=atoi(strb.c_str());
int res=0;
string r="";
for(int i=0;i<a.size();i++){
res*=10;
res+=a[i]-'0';
if(res>=b){
r=r+(char)(res/b+'0');
res=res-res/b*b;
}
else{
if(r!="")r=r+'0';
}
}
return r;
}//大数除法(大数/大数)
C++
void div_big() {}小数除法（用于求出小数点后>15位）
C++
int a,b,c,f[N],cnt[N],l,r,tend=INF;
void xiaosc(int a,int b) {//a÷b
cout<<a/b;
if(!(a%b))return ;//可以整除
cout<<'.';
int d=a%b;
for(int i=1;i;i++){
d*=10;
if(!d){//除尽了
tend=i;break;
}
if(cnt[d]){//找到循环节
l=cnt[d];r=i-1;break;
}
cnt[d]=i;
int t=d/b;
d-=t*b;
f[i]=t;
}
//输出循环节，会用括号括起来
for(int i=1;i;i++){
if(i==tend)break;
if(i==l)cout<<'(';
cout<<f[i];
if(i==r){
cout<<')';return ;
}
}
return ;
}他人版本（压位）（打包）
C++
typedef long long LL;
const int base = 1e8;
int aux[N];//储存原始数据
class HighPrecision{//高精度压位模板
private:
int p[N], sz;//类的私有成员
public://区域一:
void cin() {//读入函数
this -> clear();//清空对象
memset(aux, 0, sizeof(aux));
int tot = 0,x = 0, y, k = 1;
char ch = getchar();
int fu = 1; //符号判断
for (; ch < '0' || ch > '9'; ch = getchar())
if (ch == '-') fu *= -1;
for (; ch >= '0' && ch <= '9'; ch = getchar()){
if(tot==1&&aux[tot]==0)aux[tot] = ch - '0';
else aux[++tot] = ch - '0';//处理前缀零和读入零的情况
}
sz = (tot + 7) / 8;//计算位数
y = (tot - 1) % 8 + 1;//最高位标记
for (int i = tot; i >= y; i -= 8, x=0){
for(int j=7;j>=0;--j){//压位(亿进制)
if(i <= j)continue;//最高位处理
x = x * 10 + aux[i - j];
}
p[k++] = x;//对每一位进行储存
}
p[sz] *= fu;//标记符号
}
void cout(bool u = false){//读出函数
if(sz == 0) { printf("inf"); return;}//异常状况
printf("%d", p[sz]);//先输出首位带符号
for(int i = sz - 1; i; --i)
printf("%08d", p[i]);
if(u) printf("\n");//换行
}
public://区域二：
HighPrecision operator = (const int &d){//重载= (int)
int b = d;
int fu = 1;//符号判断
if(b < 0) b *= -1, fu = -1;
this -> clear();//清空对象
do {//用do~while处理d为零的状况
p[++sz] = b % base;
b /= base;
} while(b);
p[sz] *= fu;
return *this;
}
HighPrecision operator = (const LL &d){//重载= (long long)
LL b = d;
int fu = 1;//符号判断
if (b < 0) b *= -1, fu = -1;
this -> clear();//清空对象
do {//用do~while处理d为零的状况
p[++sz] = b % base;
b /= base;
} while(b);
p[sz] *= fu;//标记符号
return *this;
}
HighPrecision operator + (const int &d){//重载+ (int)
LL x = d;
int fu = 1;//符号判断
HighPrecision c;
if (p[sz] < 0 && x < 0) p[sz] *= -1, x *= -1, fu = -1;
else if (p[sz] < 0) {p[sz] *= -1; return (c = x) - *this;}
else if (x < 0) {x *= -1; return *this - x;}
for (int i = 1; i <= sz && x; ++i) {//进位计算
x = x + p[i];
p[i] = x % base;
x = x / base;
}
if (x) p[++sz] = x;//进位 位数+1
p[sz] *= fu;
return *this;
}
HighPrecision operator + (const LL &d){//重载+ (long long)
LL x = d;
int fu = 1;//符号判断
HighPrecision c;
if (p[sz] < 0 && x < 0) p[sz] *= -1, x *= -1, fu = -1;
else if (p[sz] < 0) {p[sz] *= -1; return (c = x) - *this;}
else if (x < 0) {x *= -1; return *this - x;}
for (int i = 1; i <= sz && x; ++i) {//进位计算
x = x + p[i];
p[i] = x % base;
x = x / base;
}
if (x) p[++sz] = x;//进位 位数+1
p[sz] *= fu;
return *this;
}
HighPrecision operator + (const HighPrecision &d){//重载+ (HighPrecision)
HighPrecision c, a = *this, b = d;
int fu = 1;//符号判断
if (a.p[a.sz] < 0 && b.p[b.sz] < 0) a.p[a.sz] *= -1, b.p[b.sz] *= -1, fu = -1;
else if (a.p[a.sz] < 0) {a.p[a.sz] *= -1; return b - a;}
else if (b.p[b.sz] < 0) {b.p[b.sz] *= -1; return a - b;}
if (a < b) a.swap(b);//a为大值,方便计算
if (b.sz < 3) {c = a + b.toLL(); c.p[c.sz] *= fu; return c;}//节省时间
LL x = 0;
for(int i = 1; i <= a.sz; ++i) {
x = x + a.p[i] + b.p[i];
c.p[i] = x % base;
x = x / base;
}
c.sz = a.sz;
if (x) c.p[++c.sz] = x;//进位 位数+1
c.p[c.sz] *= fu;//标记符号
return c;
}
HighPrecision operator - (const HighPrecision &d){//重载- (HighPrecision)
HighPrecision a = *this, c, b = d;
int fu = 1;//符号判断
if(a.p[a.sz] < 0 && b.p[b.sz] < 0) a.p[a.sz] *= -1, b.p[b.sz] *= -1, fu *= -1;
else if (a.p[a.sz] < 0) {a.p[a.sz] *= -1;c = a + b; c.p[c.sz] *= -1; return c;}
else if (b.p[b.sz] < 0) {b.p[b.sz] *= -1; return a + b;}
LL x = 1, k = 0;
if(a<b) a.swap(b), fu *= -1;
if(a == b)return c = 0;//特殊情况直接输出
for(int i = 1; i <= a.sz; ++i){//借位计算
x = x + a.p[i] + base -1 - b.p[i];
c.p[i] = x % base;
x = x / base;
}
for(c.sz = a.sz; c.p[c.sz] == 0; --c.sz);//计算c.sz
c.p[c.sz] *= fu;//符号标记
return c;
}
HighPrecision operator - (const int &d){//重载- (int)
HighPrecision c;
int b = d;
int fu = 1;//符号判断
if(p[sz] < 0 && b < 0) p[sz] *= -1, b *= -1, fu *= -1;
else if (p[sz] < 0) {p[sz] *= -1;c = *this + b; c.p[c.sz] *= -1; return c;}
else if (b < 0) {b *= -1; return *this + b;}
c=*this - (c = b);
c.p[c.sz] *= fu;//符号标记
return c;
}
HighPrecision operator - (const LL &d){//重载- (long long)
HighPrecision c;
LL b = d;
int fu = 1;//符号判断
if(p[sz] < 0 && b < 0) p[sz] *= -1, b *= -1, fu *= -1;
else if (p[sz] < 0) {p[sz] *= -1;c = *this + b; c.p[c.sz] *= -1; return c;}
else if (b < 0) {b *= -1; return *this + b;}
c=*this - (c = b);
c.p[c.sz] *= fu;//符号标记
return c;
}
HighPrecision operator * (const int &d){//重载* (int)
HighPrecision a=*this,c;
int b = d;
int fu = 1;//符号判断
if(a.p[a.sz] < 0) a.p[a.sz] *= -1, fu *= -1;
if(b < 0) b *= -1, fu *= -1;
LL x = 0;
if(b == 0||a.sz == 1 && a.p[a.sz] == 0) return c = 0;
for(int i = 1; i <= a.sz; ++i){
x = x + 1ll * a.p[i] * b;
c.p[i] = x % base;
x = x / base;
}
c.sz = a.sz;//计算c.sz
for(; x; x /= base){
c.p[++c.sz] = x % base;
}
c.p[c.sz] *= fu;//符号标记
return c;
}
HighPrecision operator * (const HighPrecision &d){//重载* (HighPrecision)
HighPrecision a =* this, b = d, c;
int fu = 1;//符号判断
if(a.p[a.sz] < 0) a.p[a.sz] *= -1, fu *= -1;
if(b.p[b.sz] < 0) b.p[b.sz] *= -1, fu *= -1;
if(a < b) a.swap(b);
if(b.sz < 2) return a * b.toLL(fu);
if(b.sz == 1 && b.p[b.sz] == 0) return c = 0;
LL x=0;
for (int i = 1; i < a.sz + b.sz || x; ++i){//按位依次求出
int l = 1, r = b.sz, k = i;
if (i <= b.sz) r = i;
if (i > a.sz) l = i - a.sz + 1, k = a.sz;
for(int j = l; j <= r; ++j, --k){
x += 1ll * a.p[k] * b.p[j]; //注意数值范围
}
c.p[++c.sz] = x % base;
x = x / base;
}
c.p[c.sz] *= fu;//符号标记
return c;
}
HighPrecision operator * (const LL &d){//重载* (long long)
HighPrecision a=*this,c;
LL b=d;
int fu = 1;//符号判断
if(a.p[a.sz] < 0) a.p[a.sz] *= -1, fu *= -1;
if(b < 0) b *= -1, fu *= -1;
if(d > 2e9) return a * (c = d);
LL x = 0;
if(b == 0||a.sz == 1 && a.p[a.sz] == 0) return c = 0;
for(int i = 1; i <= a.sz; ++i){
x = x + 1ll * a.p[i] * b;
c.p[i] = x % base;
x = x / base;
}
c.sz = a.sz;//计算c.sz
for(; x; x /= base){
c.p[++c.sz] = x%base;
}
c.p[c.sz] *= fu; //符号标记
return c;
}
HighPrecision operator / (const int &d){//重载/ (int)
HighPrecision a=*this, c;
int b=d;
int fu = 1;//判断符号
if (a.p[a.sz] < 0) a.p[a.sz] *= -1, fu *= -1;
if (b < 0) b *= -1, fu *= -1;
LL x=0;
if (b == 0) return c;//除数为零 抛出异常状况
for(int i = a.sz; i; --i){
x = x * base + a.p[i];
c.p[i] = x / b;
x = x % b;
}
for(c.sz = a.sz; c.p[c.sz] == 0 && c.sz > 1; --c.sz);
c.p[c.sz] *= fu; //符号标记
return c;
}
HighPrecision operator / (const LL &d){//重载/ (long long)
HighPrecision a=*this, c;
LL b=d;
int fu = 1;//判断符号
if (a.p[a.sz] < 0) a.p[a.sz] *= -1, fu *= -1;
if (b < 0) b *= -1, fu *= -1;
LL x=0;
if (b == 0) return c;//除数为零 抛出异常状况
for(int i = a.sz; i; --i){
x = x * base + a.p[i];
c.p[i] = x / b;
x = x % b;
}
for(c.sz = a.sz; c.p[c.sz] == 0 && c.sz > 1; --c.sz);
c.p[c.sz] *= fu;//符号标记
return c;
}
HighPrecision operator / (const HighPrecision &d){//重载/ (HighPrecision)
HighPrecision a=*this,b=d,c,ce;
int fu = 1;//判断符号
if (a.p[a.sz] < 0) a.p[a.sz] *= -1, fu *= -1;
if (b.p[b.sz] < 0) b.p[b.sz] *= -1, fu *= -1;
if(b.sz == 1 && b.p[b.sz] == 0) return c;//除数为零 抛出异常状况
if (a < b) return c = 0;//被除数小于除数
if (a == b) return c = 1;//被除数等于除数
if (b.sz < 2) return a / b.toLL(fu);
for(int i = a.sz; i; --i){
for(int j = ++ce.sz; j > 1; --j)//模拟进位
ce.p[j] = ce.p[j-1];
ce.p[1] = a.p[i];
if (ce < b) continue;//商为零 直接跳过
int l = 0, r = base, x;
while(l <= r) {//二分查找商
int mid = l + r >> 1;
if (b * mid <= ce) {
x = mid;
l = mid + 1;
}
else {
r = mid - 1;
}
}
c.p[i] = x;
ce = ce - b * x;
}
for(c.sz = a.sz; c.p[c.sz] == 0 && c.sz > 1; --c.sz);
c.p[c.sz] *= fu; //符号标记
return c;
}
HighPrecision operator % (const int &d){//重载% (int)
HighPrecision a=*this, c;
int b=d;
int fu = 1;//判断符号
if (a.p[a.sz] < 0) a.p[a.sz] *= -1, fu *= -1;
if (b < 0) b *= -1, fu *= -1;
LL x=0;
if (d == 0) return c;//除数为零 抛出异常状况
for(int i = a.sz; i; --i){
x = (x * base + a.p[i]) % b;
}
return c = x * fu;
}
HighPrecision operator % (const LL &d){//重载% (long long)
HighPrecision a=*this, c;
LL b=d;
int fu = 1;//判断符号
if (a.p[a.sz] < 0) a.p[a.sz] *= -1, fu *= -1;
if (b < 0) b *= -1, fu *= -1;
LL x=0;
if (d == 0) return c;//除数为零 抛出异常状况
for(int i = a.sz; i; --i){
x = (x * base + a.p[i]) % b;
}
return c = x * fu;
}
HighPrecision operator % (const HighPrecision &d){//重载% (HighPrecision)
HighPrecision a=*this,b=d,ce;
int fu = 1;//判断符号
if (a.p[a.sz] < 0) a.p[a.sz] *= -1, fu *= -1;
if (b.p[b.sz] < 0) b.p[b.sz] *= -1, fu *= -1;
if (b.sz == 1 && b.p[b.sz] == 0) return ce;//除数为零 抛出异常状况
if (a < b) return a;//被除数小于除数
if (a == b) return ce = 0;//被除数等于除数
if (b.sz < 2) return a % b.toLL(fu);
for(int i = a.sz; i; --i){
if (!(ce.sz == 1 && ce.p[ce.sz] == 0))
for(int j = ++ce.sz; j > 1; --j)//模拟进位
ce.p[j] = ce.p[j-1];
ce.p[1] = a.p[i];
if (ce < b) continue;//商为零 直接跳过
int l = 0, r = base, x;
while(l <= r) {//二分查找商
int mid = l + r >> 1;
if (ce < b * mid) {
r = mid - 1;
}
else {
x = mid;
l = mid + 1;
}
}
ce = ce - b * x;
}
ce.p[ce.sz] *= fu; //符号标记
return ce;
}
public://区域三：
HighPrecision operator += (int &b) {return *this = *this + b;}
HighPrecision operator -= (int &b) {return *this = *this - b;}
HighPrecision operator *= (int &b) {return *this = *this * b;}
HighPrecision operator /= (int &b) {return *this = *this / b;}
HighPrecision operator %= (int &b) {return *this = *this % b;}
HighPrecision operator += (LL &b) {return *this = *this + b;}
HighPrecision operator -= (LL &b) {return *this = *this - b;}
HighPrecision operator *= (LL &b) {return *this = *this * b;}
HighPrecision operator /= (LL &b) {return *this = *this / b;}
HighPrecision operator %= (LL &b) {return *this = *this % b;}
HighPrecision operator += (HighPrecision &b) {return *this = *this + b;}
HighPrecision operator -= (HighPrecision &b) {return *this = *this - b;}
HighPrecision operator *= (HighPrecision &b) {return *this = *this * b;}
HighPrecision operator /= (HighPrecision &b) {return *this = *this / b;}
HighPrecision operator %= (HighPrecision &b) {return *this = *this % b;}
bool operator < (const int &b) const {HighPrecision c;return *this < (c=b);}
bool operator <= (const int &b) const {HighPrecision c;return *this <= (c=b);}
bool operator > (const int &b) const {HighPrecision c;return *this > (c=b);}
bool operator >= (const int &b) const {HighPrecision c;return *this >= (c=b);}
bool operator == (const int &b) const {HighPrecision c;return *this == (c=b);}
bool operator != (const int &b) const {HighPrecision c;return *this != (c=b);}
bool operator < (const LL &b) const {HighPrecision c;return *this < (c=b);}
bool operator <= (const LL &b) const {HighPrecision c;return *this <= (c=b);}
bool operator > (const LL &b) const {HighPrecision c;return *this > (c=b);}
bool operator >= (const LL &b) const {HighPrecision c;return *this >= (c=b);}
bool operator == (const LL &b) const {HighPrecision c;return *this == (c=b);}
bool operator != (const LL &b) const {HighPrecision c;return *this != (c=b);}
bool operator == (const HighPrecision &b) const {if(sz^b.sz)return false;
for (int i=sz;i;i--) if(p[i] ^ b.p[i]) return false; return true ;}
bool operator != (const HighPrecision &b) const {if(sz^b.sz)return true ;
for (int i=sz;i;i--) if(p[i] ^ b.p[i]) return true ; return false;}
bool operator < (const HighPrecision &b) const {if(sz^b.sz)return sz<b.sz;
for (int i=sz;i;i--) if(p[i] ^ b.p[i]) return p[i] < b.p[i]; return false;}
bool operator <= (const HighPrecision &b) const {if(sz^b.sz)return sz<b.sz;
for (int i=sz;i;i--) if(p[i] ^ b.p[i]) return p[i] < b.p[i]; return true ;}
bool operator > (const HighPrecision &b) const {if(sz^b.sz)return sz>b.sz;
for (int i=sz;i;i--) if(p[i] ^ b.p[i]) return p[i] > b.p[i]; return false;}
bool operator >= (const HighPrecision &b) const {if(sz^b.sz)return sz>b.sz;
for (int i=sz;i;i--) if(p[i] ^ b.p[i]) return p[i] > b.p[i]; return true ;}
public://区域四:
HighPrecision() {clear();}//重载构造函数
HighPrecision(int x) {*this = x;}
HighPrecision(LL x) {*this = x;}
void clear() {sz = 0; memset(p, 0, sizeof(p));}//清空函数
void swap(HighPrecision &b) {HighPrecision c = *this; *this = b; b = c;}//交换函数
LL toLL(int fu = 1) {//化值函数
LL x = 0;
if (p[sz] < 0)
p[sz] *= -1, fu = -1;
for(int i=sz;i;--i)
x=x*base+p[i];
return x * fu;
}
public:
bool check(){//判偶数
if(p[1]&1)return 0;
return 1;
}
//区域一：输入输出 、区域二：四则运算 、区域三：基础配置 、区域四：辅助函数
} a, b;高精GCD
C++
//依赖上面的高精度
HighPrecision gcd(HighPrecision a,HighPrecision b){//小心爆栈哦
HighPrecision r=1;
while(b!=0){
if(a<b)swap(a,b);
// a.cout(),b.cout(1);
if(a.check()&&b.check()){
a=a/2;
b=b/2;
r=r*2;
}
else if(a.check()){a=a/2;}
else if(b.check()){b=b/2;}//多打括号&cmr
else a-=b;
}
return a*r;
}他人版本
C++
#include <iostream>
#include <string>
using namespace std;
int cmp(string, string);
string add(string, string);
string sub(string, string);
string mul(string, string);
string div(string, string);
string mod(string, string);
int main()
{
std:
ios::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
string a, b;
cin >> a >> b;
cout << add(a, b) << "\n"
<< sub(a, b) << "\n"
<< mul(a, b) << "\n"
<< div(a, b) << "\n"
<< mod(a, b) << "\n";
return 0;
}
int cmp(string str1, string str2)
{
if (str1.length() < str2.length())
return -1;
if (str1.length() > str2.length())
return 1;
return str1.compare(str2);
}
string add(string str1, string str2)
{
string str = "";
int str1_len = str1.length(), str2_len = str2.length(), temp = 0;
bool carry = 0;
if (str1_len < str2_len)
for (int i = 1; i <= str2_len - str1_len; i++)
str1 = '0' + str1;
else
for (int i = 1; i <= str1_len - str2_len; i++)
str2 = '0' + str2;
str1_len = str1.length(), str2_len = str.length();
for (int i = str1_len - 1; i >= 0; i--)
{
temp = str1[i] - '0' + str2[i] - '0' + carry;
carry = temp / 10;
temp %= 10;
str = char(temp + '0') + str;
}
if (carry == 1)
str = '1' + str;
return str;
}
string sub(string str1, string str2)
{
string str = "";
int str1_len = str1.length(), str2_len = str2.length(), temp = 0;
bool carry = 0;
if (str1_len < str2_len)
for (int i = 1; i <= str2_len - str1_len; i++)
str1 = '0' + str1;
else
for (int i = 1; i <= str1_len - str2_len; i++)
str2 = '0' + str2;
str1_len = str1.length(), str2_len = str2.length();
for (int i = str1_len - 1; i >= 0; i--)
{
temp = (str1[i] - '0') - (str2[i] - '0') - carry;
if (temp < 0)
{
carry = 1;
temp += 10;
}
else
carry = 0;
str = char(temp + '0') + str;
}
str.erase(0, str.find_first_not_of('0'));
if (str.empty())
str = "0";
return str;
}
string mul(string str1, string str2)//注意！有锅！请用上面的！
{
string str = "", temp_num = "";
int carry = 0, temp_digit = 0;
int str1_len = str1.length(), str2_len = str2.length();
for (int i = str2_len - 1; i >= 0; i--)
{
temp_num = "";
temp_num.insert(0, str2_len - 1 - i, '0');
for (int j = str1_len - 1; j >= 0; j--)
{
temp_digit = (str2[i] - '0') * (str1[j] - '0') + carry;
carry = temp_digit / 10;
temp_digit %= 10;
temp_num = char(temp_digit + '0') + temp_num;
}
if (carry != 0)
temp_num = char(carry + '0') + temp_num;
str = add(str, temp_num);
}
str.erase(0, str.find_first_not_of('0'));
if (str.empty())
str = "0";
return str;
}
string div(string str1, string str2)
{
string str = "";
int str1_len = str1.length(), str2_len = str2.length();
if (str2 == "0")
str = "ERROR";
else if (str1 == "0")
str = "0";
else if (cmp(str1, str2) < 0)
str = "0";
else if (cmp(str1, str2) == 0)
str = "1";
else
{
string dividend = "";
dividend.append(str1, 0, str2_len - 1);
for (int i = str2_len - 1; i < str1_len; i++)
{
dividend += str1[i];
dividend.erase(0, dividend.find_first_not_of('0'));
if (dividend.empty())
dividend = "0";
for (char ch = '9'; ch >= '0'; ch--)
{
string tempstr;
tempstr += ch;
string temp = mul(str2, (tempstr));
if (cmp(temp, dividend) <= 0)
{
str += ch;
dividend = sub(dividend, temp);
break;
}
}
}
str.erase(0, str.find_first_not_of('0'));
if (str.empty())
str = "0";
}
return str;
}
string mod(string str1, string str2)
{
string str;
if (str2 == "0")
str = "ERROR";
str = sub(str1, mul(div(str1, str2), str2));
return str;
}快读&快输
快速读入数字
C++
#define rd read()
inline int read(){
int xx=0,ff=1;
char ch=getchar();
while(ch<'0'||ch>'9') {if(ch=='-') ff=-1;ch=getchar();}
while(ch>='0'&&ch<='9') xx=xx*10+(ch-'0'),ch=getchar();
return xx*ff;
}
inline void write(int out){
if(out<0) putchar('-'),out=-out;
if(out>9) write(out/10);
putchar(out%10+'0');
}
C++
#define rd read()
long long read(){
long long x=0;char ch=getchar();
while(ch!=' '||ch!='\n')ch=getchar(),x=x*10+ch-'0';
return x;
}快速输出
C++
printf(); //就差不多了