hdu 3790 最短路徑問題(兩個限制條件的最短路)
阿新 • • 發佈:2018-12-24
有兩個條件:距離和花費。首先要求距離最短,距離相等的條件下花費最小。
dijkstra,只是在判斷條件時多考慮了花費。
注意重邊。
#include <stdio.h> #include <algorithm> #include <set> #include <map> #include <vector> #include <math.h> #include <string.h> #include <stack> #include <queue> #define LL long long #define _LL __int64 using namespace std; const int INF = 0x3f3f3f3f; const int maxn = 1010; int Map[maxn][maxn],cost[maxn][maxn]; int n,m; int dis1[maxn],dis2[maxn]; void init() { for(int i = 1; i <= n; i++) { for(int j = 1; j <= n; j++) { if(i == j) { Map[i][j] = 0; cost[i][j] = 0; } else { Map[i][j] = INF; cost[i][j] = INF; } } } } void dijkstra(int s, int t) { int vis[maxn]; memset(dis1,INF,sizeof(dis1)); memset(dis2,INF,sizeof(dis2)); memset(vis,0,sizeof(vis)); for(int i = 1; i <= n; i++) { dis1[i] = Map[s][i]; dis2[i] = cost[s][i]; } vis[s] = 1; for(int i = 1; i <= n; i++) { int M1= INF, M2 = INF, pos; for(int j = 1; j <= n; j++) { if(vis[j]) continue; if(dis1[j] < M1 || (dis1[j] == M1 && dis2[j] < M2)) { M1 = dis1[j]; M2 = dis2[j]; pos = j; } } vis[pos] = 1; for(int j = 1; j <= n; j++) { if(vis[j]) continue; int tmp1 = dis1[pos] + Map[pos][j]; int tmp2 = dis2[pos] + cost[pos][j]; if(tmp1 < dis1[j] || (tmp1 == dis1[j] && tmp2 < dis2[j])) { dis1[j] = tmp1; dis2[j] = tmp2; } } } } int main() { while(~scanf("%d %d",&n,&m)) { if(n == 0 || m == 0) break; init(); int a,b,d,p; while(m--) { scanf("%d %d %d %d",&a,&b,&d,&p); if(Map[a][b] == INF && cost[a][b] == INF) { Map[a][b] = Map[b][a] = d; cost[a][b] = cost[b][a] = p; } else if(d < Map[a][b] || (Map[a][b] == d && cost[a][b] > p)) { Map[a][b] = Map[b][a]= d; cost[a][b] = cost[b][a] = p; } } scanf("%d %d",&a,&b); dijkstra(a,b); printf("%d %d\n",dis1[b],dis2[b]); } return 0; }