hdu 1690 Bus System （Floyd，spfa 没一直wa）

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小记：我开始写的spfa，然后一直wa。。。后来改成Floyd，就a了。

思路：Floyd多源最短路。注意下INF的值要调大点，我的是1e18.

我的spfa不晓得哪里错了。

代码：spfa

#include <iostream>#include <stdio.h>#include <string.h>#include <math.h>#include <stdlib.h>#include <map>#include <set>#include <vector>#include <stack>#include <queue>#include <algorithm>#include <string>using namespace std;#define mst(a,b) memset(a,b,sizeof(a))#define REP(a,b,c) for(int a = b; a < c; ++a)#define eps 10e-8const int MAX_ = 101;const int N = 100010;const long long INF = 1e18;int n;struct node{    int s, t;}p[MAX_*30];int g[MAX_][MAX_], tmp[MAX_];long long d[MAX_];bool vis[MAX_];int m, cnt, L[5],C[5];void spfa(int start){    queue<int > q;    REP(i, 0, n+1){        vis[i] = 0;        d[i] = INF;    }    vis[start] = 1;    d[start] = 0;    q.push(start);    while(!q.empty()){        int cur = q.front(); q.pop();        vis[cur] = 0;        REP(i, 0, n){            if(g[cur][i]  && d[i] > d[cur] + g[cur][i]){                d[i] = d[cur] + g[cur][i];                if(!vis[i]){                    vis[i] = 1;                    q.push(i);                }            }        }    }    return ;}int main(){    int T, ss, tt, v, Ca = 0, s, t;    char str[10];    scanf("%d", &T);    while(T-- &&scanf("%d%d%d%d%d%d%d%d",                   &L[1],&L[2],&L[3],&L[4],&C[1],&C[2],&C[3],&C[4])){        scanf("%d%d", &n, &m);        //mst(g, 0);        REP(i, 0, n){            scanf("%d", &tmp[i]);        }        REP(i, 0, n){            long long s, t;            s = tmp[i];            REP(j, i+1, n){                t = s- tmp[j];                if(t < 0)t = -t;                int temp = 0;                REP(k, 1, 5){                    if(t <= L[k]){temp = C[k];break;}                }                g[i][j] = g[j][i] = temp;            }        }/*        REP(i, 0, n){            REP(j, 0, n){                printf("%d ", g[i][j]);            }putchar('\n');        }*/<span style="white-space:pre"></span>printf("Case %d:\n", ++Ca);        REP(i, 0, m){            scanf("%d%d", &s, &t);            spfa(s-1);            long long ans = d[t-1];            if(ans == INF){                printf("Station %d and station %d are not attainable.\n", s, t);            }            else            printf("The minimum cost between station %d and station %d is %I64d.\n", s, t, ans);        }    }    return 0;}

Floyd：

#include <iostream>#include <stdio.h>#include <string.h>#include <math.h>#include <stdlib.h>#include <map>#include <set>#include <vector>#include <stack>#include <queue>#include <algorithm>#include <string>using namespace std;#define mst(a,b) memset(a,b,sizeof(a))#define REP(a,b,c) for(int a = b; a < c; ++a)#define eps 10e-8const int MAX_ = 101;const int N = 100010;//const int INF = 0x7fffffff;const  long long INF = 1e18;int n;struct node{    int s, t;}p[MAX_*30];long long g[MAX_][MAX_], L[5],C[5], tmp[MAX_];long long d[MAX_];bool vis[MAX_];int m, cnt;long long find(int t){    REP(k, 1, 5){        if(t <= L[k]){return C[k];}    }    return INF;}void floyd(){    REP(k, 0, n)REP(i, 0, n)REP(j, 0, n){        if(g[i][j] > g[i][k] + g[k][j]){            g[i][j] =  g[i][k] + g[k][j];        }    }}int main(){int T, ss, tt, v, Ca = 0, s, t;char str[10];scanf("%d", &T);while(T-- &&scanf("%I64d%I64d%I64d%I64d%I64d%I64d%I64d%I64d",                   &L[1],&L[2],&L[3],&L[4],&C[1],&C[2],&C[3],&C[4])){        scanf("%d%d", &n, &m);        REP(i, 0, n)REP(j, 0, n)g[i][j] = INF;        REP(i, 0, n){            scanf("%I64d", &tmp[i]);        }        REP(i, 0, n){            long long s, t;            s = tmp[i];            REP(j, i+1, n){                t = s- tmp[j];                if(t < 0)t = -t;                /*long long temp;                REP(k, 0, 4){                    if(t <= L[k]){temp = C[k];break;}                }*/                g[i][j] = g[j][i] = find(t);            }        }/*        REP(i, 0, n){            REP(j, 0, n){                printf("%I64d ", g[i][j]);            }putchar('\n');        }*/        floyd();        /*        REP(i, 0, n){            REP(j, 0, n){                printf("%I64d ", g[i][j]);            }putchar('\n');        }*/        printf("Case %d:\n", ++Ca);        REP(i, 0, m){            scanf("%d%d", &s, &t);            //spfa(s-1);            //long long ans = d[t-1];            if(g[s-1][t-1] == INF){                printf("Station %d and station %d are not attainable.\n", s, t);            }            else            printf("The minimum cost between station %d and station %d is %I64d.\n", s, t, g[s-1][t-1]);        }}return 0;}

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