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#include <cmath> #include <iostream> #include <cstring> #include <string> #include <stdio.h> #include <string.h> #include <ctype.h> #include <vector> #include <queue> #define MAXN 0x3f3f3f3f //Dijasktra using namespace std; int roadmap[205][205]; bool vis[205]; int sr[205]; int main(){ int n = 0,m = 0; while (cin >> n >> m && m+n) { memset(roadmap, 0x3f3f, sizeof(roadmap)); memset(sr, 0x3f3f, sizeof(sr)); memset(vis, 0, sizeof(vis)); for (int i = 0; i < n; i++) { roadmap[i][i] = 0; } for (int i = 1; i <= m; i++) { int a = 0,b = 0,c = 0; cin >> a >> b >> c; if (roadmap[a][b] > c){ roadmap[a][b] = c; roadmap[b][a] = c; } } int s = 0,t = 0; cin >> s >> t; sr[s] = 0; while (true) { int i = -1; for (int q = 0; q < n; q++) { if (!vis[q]) { if (i == -1 || sr[q] < sr[i]) { i = q; } } } if (i == -1) break; for (int q = 0; q < n; q++){ sr[q] = min(sr[i]+roadmap[i][q],sr[q]); } vis[i] = true; } if (sr[t] == MAXN) { sr[t] = -1; } cout << sr[t] << endl; } return 0; } |
这是个裸的最短路问题,随便怎么搞都行。
这里用的是没有堆优化的dijkstra。