一本通 1232 Crossing River 尚贤写的

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#define F(i, n, m) for (int i = n; i <= m; ++i)
#define UF(i, n, m) for (int i = n; i >= m; --i)
#define SIZE (int)1e5 + 10
using namespace std;
int dp[SIZE];

int f1(int);
int main() {
	freopen("cpp.in", "r", stdin);
	freopen("cpp.out", "w", stdout);
	int t;
	scanf("%d", &t);
	while (t--) {
		memset(dp, 0, sizeof(dp));
		int n;
		scanf("%d", &n);
		F(i, 1, n) {
			scanf("%d", &dp[i]);
		}
		sort(dp + 1, dp + n + 1);
		printf("%d\n", f1(n));
	}
	return 0;
}

int f1(int n) {
	if (n == 1 || n == 2) {
		return dp[n];
	}
	if (n == 3) {
		return dp[1] + dp[2] + dp[3];
	} 
	return f1(n - 2) + min(dp[1] + dp[1] + dp[n - 1] + dp[n], dp[1] + dp[2] + dp[2] + dp[n]);
}

dp实现，参考：

https://www.jianshu.com/p/84608db757b4