1 介绍
本专题用来记录使用prim算法或kruskal算法求解的题目。
2 训练
题目1:1140最短网络
C++代码如下,
#include <iostream>
#include <cstring>
using namespace std;
const int N = 110, INF = 0x3f3f3f3f;
int g[N][N];
int d[N];
bool st[N];
int n, m;
void prim() {
memset(d, 0x3f, sizeof d);
int res = 0;
for (int i = 0; i < n; ++i) {
int t = -1;
for (int j = 1; j <= n; ++j) {
if (!st[j] && (t == -1 || d[t] > d[j])) {
t = j;
}
}
st[t] = true;
if (i) res += d[t];
for (int j = 1; j <= n; ++j) {
if (d[j] > g[t][j]) {
d[j] = g[t][j];
}
}
}
cout << res << endl;
return;
}
int main() {
cin >> n;
for (int i = 1; i <= n; ++i) {
for (int j = 1; j <= n; ++j) {
cin >> g[i][j];
}
}
prim();
return 0;
}
题目2:1141局域网
C++代码如下,
#include <iostream>
#include <cstring>
#include <algorithm>
using namespace std;
const int N = 110, M = 210;
int p[N];
int n, m;
struct Edge {
int a, b, w;
bool operator<