Whu 1603——Minimum Sum——————【单个元素贡献、滑窗】

#include<stdio.h>
#include<algorithm>
#include<string.h>
#include<vector>
#include<iostream>
using namespace std;
const int maxn = 1e5+200;
typedef long long LL;
int a[maxn], sum[maxn];
int main(){
    int n, m;
    while(scanf("%d%d",&n,&m)!=EOF){
        for(int i = 1; i <= n; i++){
            scanf("%d",&a[i]);
        }
        sort(a+1,a+1+n);
        for(int i = 1; i <= n; i++){
            sum[i] = sum[i-1]+a[i];
        }
        int ans = 0, tmp;
        for(int i = 2; i <= m; i++){
            ans += a[i]*(i-1) - (sum[i-1] - sum[0]);
        }
        tmp = ans;
        if(n == m){
            printf("%d\n",ans); continue;
        }
        for(int i = m+1; i <= n; i++){
            tmp = tmp + a[i]*(m-1) - (sum[i-1] - sum[i-m]) - ((sum[i-1]-sum[i-m]) - a[i-m]*(m-1));
            ans = min(ans,tmp);
        }
        printf("%d\n",ans);
    }
    return 0;
}