首页 > 代码库 > UVA10273 - Eat or Not to Eat?(暴力)

UVA10273 - Eat or Not to Eat?(暴力)

UVA10273 - Eat or Not to Eat?(暴力)

题目链接

题目大意:一个农场的主人为了改善收入决定每天要将产量最少的那一头牛杀掉,但是如果这一天出现了多只产量最小的牛,那么这一天一头也不杀。然后给你n头牛,给你每头牛的产量周期和周期内的产量,问多少天后可以确定剩余的牛的情况。

解题思路:求出这n头牛的周期的最小公倍数,那么在这个周期内,如果没有牛被杀的话,那么之后的情况是循环的,不会再有牛被杀了,这样情况就确定下来了。在这样的条件下,暴力就不会超时。

代码:

#include <cstdio>
#include <cstring>

using namespace std;

const int N = 1005;
const int M = 15;
const int maxn = 255;

int Milk[N][M];
int cnt[N];
int vis[N];
int survice[N];
int n;

int gcd (int a, int b) {

    return b == 0 ? a : gcd (b, a % b);
}

int f() {

    int T = 1;
    int tmp;
    for (int i = 0; i < n; i++) {
        if (vis[i])
            continue;
        if (T > cnt[i])
            tmp = gcd(T, cnt[i]);
        else
            tmp = gcd(cnt[i], T);
        T = T * cnt[i] / tmp;
    }
    return T;
}

int solve () {

    int T = f();
    memset (vis, 0, sizeof (vis));
    //    memset (survice, -1, sizeof (survice));
    survice[n] = 0;
    int num = n;
    for (int p = 0;; p++) {

        bool flag = 0;
        for (int i = 1; i <= T; i++) {

            int minnum = maxn;
            int tmp = 0;
            for (int j = 0; j < n; j++) {

                if (vis[j]) 
                    continue;
                int d = (i % cnt[j]) == 0 ? cnt[j] : (i % cnt[j]);
                if (minnum > Milk[j][d]) {
                    minnum = Milk[j][d];
                    tmp = j;
                } else if (minnum == Milk[j][d])
                    tmp = -1;    
            }

            if (tmp != -1) {
                vis[tmp] = 1;
                num--;
                survice[num] = p * T + i;;
                flag = 1;
            }
        }
        if (!flag)
            return num;
    }
}

int main () {

    int cas, d;
    scanf ("%d", &cas);
    while (cas--) {

        scanf ("%d", &n);
        for (int i = 0; i < n; i++) {

            scanf ("%d", &cnt[i]);
            for (int j = 1; j <= cnt[i]; j++)
                scanf ("%d", &Milk[i][j]);
        }
        int ans = solve();
        printf ("%d %d\n", ans, survice[ans]);
    }
    return 0;
}

UVA10273 - Eat or Not to Eat?(暴力)