poj 1502 MPI Maelstrom 最短路

题意：求其试点发出的到其他各点的最短路的最大值。

分析：最短路

#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;
#define re(i,n) for(int i=0;i<n;i++)
#define re1(i,n) for(int i=1;i<=n;i++)
#define inf (1<<29)
const int maxn = 110;
int map[maxn][maxn] , dist[maxn] , sta[maxn];
char c[maxn];
bool mark[maxn];
int n;
void spfa() {
    int top = 0;
    re(i,n) dist[i] = inf;
    memset(mark,false,sizeof(mark));
    dist[0] = 0;
    mark[0] = true;
    sta[++top] = 0;
    while(top > 0) {
        int u = sta[top --];
        mark[u] = false;
        re(i,n) if(dist[u] + map[u][i] < dist[i]) {
            dist[i] = dist[u] + map[u][i];
            if(!mark[i]) {
                mark[i] = true;
                sta[++top] = i;
            }
        }
    }
}
void input() {
    re1(i,n-1) re(j,i) {
        scanf("%s",c);
        if(c[0] == 'x') map[i][j] = map[j][i] = inf;
        else map[i][j] = map[j][i] = atoi(c);
    }
}
void output() {
    int ans = 0;
    re1(i,n-1) if(dist[i] > ans) ans = dist[i];
    printf("%d\n",ans);
}
int main() {
    while(~scanf("%d",&n)) {
        input();
        spfa();
        output();
    }
    return 0;
}