UVALive - 4731 Cellular Network_mimo communication for cellular networks 程序-优快云博客

本文链接：https://blog.youkuaiyun.com/hhhhhh_12/article/details/77484232

本文介绍了解决UVALive-4731问题的动态规划方法，通过计算前缀和并使用三重循环来更新状态矩阵dp[i][j]，最终求得最小化平均成本的解决方案。

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dp[i][j] = min(dp[i][j], dp[k-1][j-1]+i*(sum[i]-sum[k-1]))

sum表示将n个数从大到小排序后的前缀和

#include <stdio.h>
#include <string.h>
#include <iostream>
#include <algorithm>
#include <vector>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <string>
#include <math.h>
#include <stdlib.h>
#include <time.h>
#include <bitset>
#define INF 0x3f3f3f3f
#define eps 1e-6
#define PI 3.1415926
#define mod 1000000007
#define base 2333
using namespace std;
typedef long long LL;
const int inf = 1e9;
const int maxn = 1e2 + 10;
const int maxx = 5e6 + 10;
int t, n, m, a[maxn], sum[maxn], dp[maxn][maxn];

bool cmp(int a, int b) {
    return a > b;
}

void solve() {
    scanf("%d", &t);
    while(t--) {
        scanf("%d%d", &n, &m);
        for(int i = 1; i <= n; i++)
            scanf("%d", &a[i]);
        sort(a+1, a+n+1, cmp);
        memset(sum, 0, sizeof(sum));
        memset(dp, INF, sizeof(dp));
        for(int i = 1; i <= n; i++)
            sum[i] = sum[i-1]+a[i];
        dp[0][0] = 0;
        for(int i = 1; i <= n; i++) {
            for(int j = 1; j <= m; j++) {
                for(int k = 1; k <= i; k++)
                    dp[i][j] = min(dp[i][j], dp[k-1][j-1]+i*(sum[i]-sum[k-1]));
            }
        }
        printf("%.4f\n", dp[n][m]*1.0/sum[n]);
    }
}

int main() {
    //srand(time(NULL));
    //freopen("perechi3.in","r",stdin);
    //freopen("perechi3.out","w",stdout);
    solve();
}