#include <bits/stdc++.h>
using namespace std;
const int N = 1010;
int a[N];
int n;
void quicksort(int l, int r) {
if (l >= r) {
return;
}
int x = a[l];
int i = l, j = r + 1;
while (i < j) {
do i++; while (i <= r && a[i] <= x);
do j--; while (a[j] > x);
if (i < j) {
swap(a[i], a[j]);
}
}
swap(a[l], a[j]);
for (int i = 1; i <= n; i++) {
cout << a[i] << " ";
}cout << endl;
quicksort(l, j - 1);
quicksort(j + 1, r);
}
int main() {
cin >> n;
for (int i = 1; i <= n; i++) {
cin >> a[i];
}
quicksort(1, n);
for (int i = 1; i <= n; i++) {
cout << a[i] << " ";
}
cout << endl;
return 0;
}
B 网络布线
亚洲杯赛期间需要保证运动员公寓网络畅通，以使运动员都能正常上网。
假定公寓楼内有n个房间，编号为0...n−1，每个房间都需要网络连接。房间 i 有网络，当且仅当满足如下2个条件之一：
（1）房间 i 安装了路由器（成本为 ri>0）
（2）房间 i 和房间 j 有网线连接且房间 j 有网络（在房间 i 和房间 j 之间布置网线的成本为 fij>0）
#include<bits/stdc++.h>
using namespace std;
const int N = 3e5 + 10;
int p[N];
int n, m;
int ans;
struct edge {
int a, b, w;
bool operator<(edge& W) {
return w <W. w;
}
}e[N];
int find(int x) {
if (p[x] != x) {
p[x] = find(p[x]);
}
return p[x];
}
void solve()
{
cin >> n >> m;
for (int i = 0;i <= n;i++) {
p[i] = i;
}
int cnt = 0;
for (int i = 1;i <= n;i++) {
int k;
cin >> k;
cnt++;
e[cnt].a = i - 1;
e[cnt].b = n;
e[cnt].w = k;
}
for (int i = 1;i <= m;i++) {
int a, b, c;
cin >> a >> b >> c;
cnt++;
e[cnt].a = a;
e[cnt].b = b;
e[cnt].w = c;
}
sort(e + 1, e + cnt+1);
for (int i = 1;i <= cnt;i++) {
//cout << e[i].w << endl;
int x = find(e[i].a);
int y = find(e[i].b);
if (x != y) {
ans += e[i].w;
p[x] = y;
}
}
cout << ans;
}
int main()
{
ios::sync_with_stdio(0);
cin.tie(0), cout.tie(0);
solve();
return 0;
}
prim：
cpp复制代码
#include<bits/stdc++.h>
using namespace std;
const int N=650,M = 3e5 + 10;
int h[N], e[M], w[M], ne[M], idx;
int dist[N], st[N];
int n, m;
int ans;
void add(int a, int b, int c)
{
e[idx] = b, w[idx] = c, ne[idx] = h[a], h[a] = idx++;
}
void prim()
{
memset(st, 0, sizeof st);
memset(dist, 0x3f, sizeof dist);
dist[0] = 0;
//cout << 1 << endl;
for (int i = 0; i <= n; i++) {
int t = -1;
//cout << 1 << endl;
for (int j = 0; j <= n; j++) {
if (!st[j] && (t == -1 || dist[j] < dist[t])) {
t = j;
}
}
st[t] = 1;
ans += dist[t];
for (int j = h[t]; ~j; j = ne[j]) {
int k = e[j];
if (w[j] < dist[k]) {
dist[k] = w[j];
}
}
}
}
void solve()
{
cin >> n >> m;
memset(h, -1, sizeof h);
int cnt = 0;
for (int i = 0; i < n; i++) {
int k;
cin >> k;
add(n, i, k);
add(i, n, k);
}
for (int i = 1; i <= m; i++) {
int a, b, c;
cin >> a >> b >> c;
add(a, b, c);
add(b, a, c);
}
//cout << 1 << endl;
prim();
cout << ans;
}
int main()
{
ios::sync_with_stdio(0);
cin.tie(0), cout.tie(0);
solve();
return 0;
}
堆优化后的prim：
cpp复制代码
#include<bits/stdc++.h>
using namespace std;
const int N=650,M = 3e5 + 10;
int h[N], e[M], w[M], ne[M], idx;
int dist[N], st[N];
int n, m;
int ans;
priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> q;
void add(int a, int b, int c)
{
e[idx] = b, w[idx] = c, ne[idx] = h[a], h[a] = idx++;
}
void prim()
{
memset(st, 0, sizeof st);
memset(dist, 0x3f, sizeof dist);
q.push({ 0, 0 });
dist[0] = 0;
while (q.size())
{
auto t = q.top();
q.pop();
int ver = t.second, distance = t.first;
if (st[ver]) {
continue;
}
st[ver] = 1;
ans += distance;
for (int i = h[ver]; ~i; i = ne[i]) {
int j = e[i];
if (dist[j] > w[i]) {
dist[j] = w[i];
q.push({ dist[j], j });
}
}
}
}
void solve()
{
cin >> n >> m;
memset(h, -1, sizeof h);
int cnt = 0;
for (int i = 0; i < n; i++) {
int k;
cin >> k;
add(n, i, k);
add(i, n, k);
}
for (int i = 1; i <= m; i++) {
int a, b, c;
cin >> a >> b >> c;
add(a, b, c);
add(b, a, c);
}
//cout << 1 << endl;
prim();
cout << ans;
}
int main()
{
ios::sync_with_stdio(0);
cin.tie(0), cout.tie(0);
solve();
return 0;
}
