学步园

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-8

const 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-8

const 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;
}