Timus 1291 Gear-wheels

题目：Gear-wheels

题意：读入N ((1 ≤ N ≤ 1000) 表示有N个齿轮，随后N行，每一行读入Ki， 表示第N个齿轮的数目，随后读入若干个数（0结束），表示第 i 个齿轮与其相接。最后一行读入M、V，表示第M个齿轮与发动机相连通，发动机转速为V，求所有齿轮的速度。

解法：直接暴力地从M开始搜索，通过M来计算其他齿轮的转速，注意如果是0，要输出“0/1”

#include <iostream>
using namespace std;

const int maxn = 1010;

int map[maxn][maxn] = {0}, a[maxn], ans[maxn][3], n, d[maxn];
bool f[maxn];

int gdb(int x, int y) {
while (y != 0) {
int temp = y;
y = x%y;
x = temp;
}
return x;
}

int main() {

cin >> n;
for (int i = 1; i <= n; i++) {
f[i] = true;
cin >> a[i];
int x;
cin >> x;
while (x != 0) {
map[i][x] = 1;
cin >> x;
}
ans[i][2] = 1;
}
int m;
cin >> m;
f[m] = false;
cin >> ans[m][1];
ans[m][2] = 1;
ans[m][0] = 1;
d[1] = m;
int l = 0, r = 1;
while (l < r) {
l++;
int x = d[l];
for (int i = 1; i <= n; i++) if (map[x][i] && f[i]) {
f[i] = false;
d[++r] = i;
ans[i][0] = ans[x][0]*-1;
ans[i][1] = ans[x][1]*a[x];
ans[i][2] = ans[x][2]*a[i];
int t = gdb(ans[i][1], ans[i][2]);
ans[i][1] /= t;
ans[i][2] /= t;
}
}
for (int i = 1; i <= n; i++) {
cout << ans[i][0]*ans[i][1] << "/" << ans[i][2] << endl;
}

}