UVA10048 - Audiophobia(Floyd,最大值的最小化）

UVA10048 - Audiophobia(Floyd,最大值的最小化）

UVA10048 - Audiophobia

题目大意:给定一无向图，每条边都有一个权值，现在给你起点和终点，要求你找出起点到终点途经的边的最大值，要求这个值尽量小，到不了输出no path。

解题思路：在floyd过程中，就可以记录下来。G【i】【j】 = min(G【i】【j】, max(G【i】【k】, G【k】【j】));

代码：

#include <cstdio>

const int maxn = 105;
const int MAXD = 0x7f7f7f7f;

int C, S, Q;
int G[maxn][maxn];

int min (const int a, const int b) {
return a < b ? a : b;
}

int max(const int a, const int b) {
return a > b ? a : b;
}

void init () {

for (int i = 1; i <= C; i++)
for (int j = 1; j <= C; j++)
G[i][j] = (i == j) ? 0: MAXD;
}

void Floyd() {

for (int k = 1; k <= C; k++)
for (int i = 1; i <= C; i++)
for (int j = 1; j <= C; j++) {
if (G[i][k] == MAXD || G[k][j] == MAXD)
continue;
G[i][j] = min(G[i][j], max(G[i][k],G[k][j]));
}
}

int main () {

int T = 0;
while (scanf ("%d %d %d", &C, &S, &Q) && (C, S, Q)) {

if (T)
printf ("\n");

init();
int c1, c2, d;
for (int i = 0; i < S; i++) {
scanf("%d %d %d", &c1, &c2, &d);
G[c1][c2] = G[c2][c1] = d;
}

Floyd();

printf ("Case #%d\n", ++T);
while (Q--) {
scanf ("%d%d", &c1, &c2);
if (G[c1][c2] == MAXD)
printf ("no path\n");
else
printf ("%d\n", G[c1][c2]);
}
}
return 0;
}