题目描述
给定两个正整数（不含前导 0），计算它们的和。
输入格式
共两行，每行包含一个整数。
输出格式
共一行，包含所求的和。
数据范围
1≤整数长度≤100000
输入样例：
cpp
12
23输出样例：
cpp
35C++
cpp
#include <iostream>
#include <string>
using namespace std;
void reverse(string &s) {
size_t n = s.length();
for (int i = 0; i < n / 2; ++i) {
swap(s[i], s[n - i - 1]);
}
}
string add(string &a, string &b) {
reverse(a);
reverse(b);
size_t n = max(a.size(), b.size()), carry = 0;
string result;
for (size_t i = 0; i < n; ++i) {
if (i < a.size()) carry += a[i] - '0';
if (i < b.size()) carry += b[i] - '0';
result.push_back(carry % 10 + '0');
carry /= 10;
}
if (carry) result.push_back(carry + '0');
reverse(result);
return result;
}
int main() {
string a, b;
cin >> a >> b;
cout << add(a, b) << endl;
return 0;
}
cpp
#include <iostream>
#include <string>
#include <algorithm> // std::reverse
using namespace std;
// 实现大整数相加的函数
string add(string &a, string &b) {
// 反转字符串，使得从最低位开始相加
reverse(a.begin(), a.end());
reverse(b.begin(), b.end());
size_t n = max(a.size(), b.size()), carry = 0;
string result;
for (size_t i = 0; i < n; i++) {
if (i < a.size()) carry += a[i] - '0';
if (i < b.size()) carry += b[i] - '0';
result.push_back(static_cast<char>(carry % 10 + '0'));
carry /= 10;
}
// 处理最高位的进位
if (carry) result.push_back(static_cast<char>(carry + '0'));
// 将结果反转回正确的顺序
reverse(result.begin(), result.end());
return result;
}
int main() {
string a, b;
cin >> a >> b;
cout << add(a, b) << endl;
return 0;
}
cpp
#include <iostream>
#include <vector>
using namespace std;
vector<int> add(vector<int> &A, vector<int> &B) {
if (A.size() < B.size()) return add(B, A);
vector<int> C;
int t = 0;
for (size_t i = 0; i < A.size(); i++) {
t += A[i];
if (i < B.size()) t += B[i];
C.push_back(t % 10);
t /= 10;
}
if (t) C.push_back(t);
return C;
}
int main() {
string a, b;
vector<int> A, B;
cin >> a >> b;
for (size_t i = a.size(); i > 0; i--) A.push_back(a[i - 1] - '0');
for (size_t i = b.size(); i > 0; i--) B.push_back(b[i - 1] - '0');
auto C = add(A, B);
for (size_t i = C.size(); i > 0; i--) cout << C[i - 1];
cout << endl;
return 0;
}
cpp
#include <iostream>
#include <vector>
using namespace std;
vector<int> add(vector<int> &A, vector<int> &B)
{
if (A.size() < B.size()) return add(B, A);
vector<int> C;
int t = 0;
for (int i = 0; i < A.size(); i ++ )
{
t += A[i];
if (i < B.size()) t += B[i];
C.push_back(t % 10);
t /= 10;
}
if (t) C.push_back(t);
return C;
}
int main()
{
string a, b;
vector<int> A, B;
cin >> a >> b;
for (int i = a.size() - 1; i >= 0; i -- ) A.push_back(a[i] - '0');
for (int i = b.size() - 1; i >= 0; i -- ) B.push_back(b[i] - '0');
auto C = add(A, B);
for (int i = C.size() - 1; i >= 0; i -- ) cout << C[i];
cout << endl;
return 0;
}Go
go
package main
import (
"fmt"
"strings"
)
func reverse(s string) string {
r := []rune(s)
l := len(r)
for i := 0; i < l/2; i++ {
r[i], r[l-i-1] = r[l-i-1], r[i]
}
return string(r)
}
func max(i int, j int) int {
if i > j {
return i
}
return j
}
func add(a, b string) string {
a = reverse(a)
b = reverse(b)
n := max(len(a), len(b))
var carry uint8 = 0
var res strings.Builder
for i := 0; i < n; i++ {
if i < len(a) {
carry += a[i] - '0'
}
if i < len(b) {
carry += b[i] - '0'
}
res.WriteByte(carry%10 + '0')
carry /= 10
}
if carry > 0 {
res.WriteByte(carry + '0')
}
return reverse(res.String())
}
func main() {
var a, b string
fmt.Scanln(&a)
fmt.Scanln(&b)
fmt.Println(add(a, b))
}模板
cpp
// C = A + B, A >= 0, B >= 0
vector<int> add(vector<int> &A, vector<int> &B)
{
if (A.size() < B.size()) return add(B, A);
vector<int> C;
int t = 0;
for (int i = 0; i < A.size(); i ++ )
{
t += A[i];
if (i < B.size()) t += B[i];
C.push_back(t % 10);
t /= 10;
}
if (t) C.push_back(t);
return C;
}