Description
Tom is a student in Shan Dong Normal University! his University in the suburbs,this day,Tom wanted to go to the downtown to visit his old friend Jerry,But tom faced a problem ,he want to know how to reach the city center fastest,now the bus stations of city are n[2,100], there are m[1,1000] bus routes in the city
Tom in the 1st bus station,Jerry in the Nth bus station
Input
The fist line is m,n;
Next m lines is a,b,c (a,b is the name of bus station , c is the time you cost from station a to station b)
Output
The shortest time tom reach city center
Sample Input
1 2 1 2 10 3 4 1 2 10 2 3 10 3 4 10
Sample Output
10 30
Source
Unknown
#include <cstdio> #include <iostream> #include <cmath> #include <string> #include <cstring> #include <algorithm> using namespace std; #define ll long long const int inf = 0x3f3f3f3f; const int maxn = 1e3+8; int n, m, cost[maxn][maxn], time[maxn]; bool sign[maxn]; void dij(int s) { fill(time, time+n+1, inf); fill(sign, sign+n+1, 0); time[1] = 0; for(int i = 1; i <= n; i++) { int miao, ying = inf; for(int j = 1; j <= n; j++) if(!sign[j] && time[j] <= ying) ying = time[miao = j]; sign[miao] = 1; for(int j = 1; j <= n; j++) if(time[j]>time[miao]+cost[miao][j]) time[j] = time[miao]+cost[miao][j]; } } int main() { while(~scanf("%d%d", &m, &n) && (n+m)) { for(int i = 1; i <= n; i++) for(int j = 1; j <= n; j++) cost[i][j] = inf; int a, b, c; while(m--) { scanf("%d%d%d", &a, &b, &c); if(cost[a][b]>c) cost[a][b] = cost[b][a] = c; } dij(1); printf("%d ", time[n]); } return 0; }