#include<bits/stdc++.h>
using namespace std;
typedef long long ll;

const int maxn = 1007;

int n, c, val[maxn];
ll pre_sum[maxn], max_Ans;

void dfs(int m, long long cnow) {
	if (cnow + pre_sum[m - 1] <= c) {
		max_Ans = max(max_Ans, cnow + pre_sum[m - 1]);
		return;
	}
	if (cnow + pre_sum[m - 1] < max_Ans)return;
	for (int i = m - 1; i >= 1; i--) {
		if (cnow + val[i] > c)continue;
		dfs(i, cnow + val[i]);
	}
	return;
}
int main() {
	freopen("P5194_3.in", "r", stdin);
	cin >> n >> c;
	long long sum = 0;
	for (int i = 1; i <= n; i++) {
		cin >> val[i];
		pre_sum[i] = pre_sum[i - 1] + val[i];
		sum += val[i];
	}
	dfs(n + 1, 0);
	cout << max_Ans;
}

用了#4和#6的数据测试

#4

ans：$1007965426$

my output：$1007965425$

#6

ans：$1054172650$

my output：$1054172649$

每次都差1 但是不知道问题出在哪了 求大佬帮助