hdu 1217 Arbitrage 【floyd】

来源：互联网发布：mac地址采集摄像机编辑：程序博客网时间：2024/05/21 21:43

题目链接：http://acm.acmcoder.com/showproblem.php?pid=1217

floyd传递闭包。

代码：

#include <iostream>#include <stdio.h>#include <string.h>#include <algorithm>#include <math.h>#include <string>#include <set>#include <queue>#include <stack>#include <vector>#include <map>using namespace std;char a[100], b[100];double c;int n, m;int f, q;double Map[110][110];struct{    int num;    char s[110];}p[35];void init(){    memset(Map, 0, sizeof(Map));    for (int i = 0; i < n; i++)    {        Map[i][i] = 1;        scanf("%s", p[i].s);        p[i].num = i;    }    scanf("%d",&m);    while (m--)    {        scanf("%s %lf %s", a, &c, b);        for (int i = 0; i < n; i++)        {            if (strcmp(a, p[i].s) == 0)                f = i;            if (strcmp(b, p[i].s) == 0)                q = i;        }        Map[f][q] = c; //Map[q][f] = 1.0 / c;    }}int solve(){    for (int k = 0; k < n;k++)        for (int i = 0; i < n; i++)            for (int j = 0; j < n; j++)            {                if (Map[i][k] != 0 && Map[k][j] != 0 && Map[i][j] < Map[i][k] * Map[k][j])                {                    Map[i][j] = Map[i][k] * Map[k][j];                }            }    for (int i = 0; i < n; i++)        if (Map[i][i] > 1)                return 1;    return 0;}int cases = 1;int main(){    while (scanf("%d", &n) != EOF && n)    {        init();        if (solve() == 1)            printf("Case %d: Yes\n",cases++);        else             printf("Case %d: No\n", cases++);    }    return 0;}

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