POJ 2485 Highways (MST.Prim)

赤裸裸的MST问题。

#include<iostream>#include<cstdio>#define FOR(i, n) for(int i = 0; i < (n); i++)using namespace std;int cost[500][500];bool inTree[500];void init(int N){FOR(i, N)FOR(j, N)scanf("%d", &cost[i][j]);FOR(i, N)inTree[i] = false;}int main(){int T;scanf("%d", &T);while(T--){int N;scanf("%d", &N);init(N);int index;int result = -1;inTree[0] = true;FOR(a, N - 1){int MIN = 100000;FOR(i, N){if(inTree[i])FOR(j, N){if(!inTree[j] && cost[i][j] < MIN){index = j;MIN = cost[i][j];}}}if(result < MIN)result = MIN;inTree[index] = true;}printf("%d\n", result);}}