题目。

感觉思路没错，但 64 分，求大佬纠正！

#include <bits/stdc++.h>
using namespace std;
#define int long long
int n;
int r;
bool f, f1;
int b[1000001];
int s[100001];
int c[100001];
int ans;
int xx, yy;
void inint() {
    s[0] = 0;
	f = f1 = 0;
	for (int i = 1; i <= n; i++) {
		cin >> c[i];
		if (c[i] < 0) f = 1;
		if (c[i] > 0) f1 = 1;
		s[i] = s[i - 1] + c[i];
	}
}
int fu() {
	int ans  = 0;
	for (int i = 1; i <= n; i++) {
		int t = s[n] - s[i] - c[i];
		ans =  max(t, ans);
	}
	return ans;
}

int zheng() {
	int ans  = 0;
	for (int i = 1; i <= n ; i++) {
		int t = -s[i]  + s[n - 1] + c[i];
		ans =  max(t, ans);
	}
	return ans;
}
int zero() {
	int ans = 0;
	int t = 0;
	xx = yy = 0;
	for (int i = 1; i <= n; i++)
		if (c[i] < 0) {
			xx = i;
			break;
		}
	xx--;
	for (int i = n; i >= 1; i--)if (c[i] > 0) {
			yy = i;
			break;
		}
	yy++;
	t = 0;
	if (xx > 0)
		for (int i = 1; i <= xx; i++) {
			t = max(t, s[xx] - s[i] - c[i]);
		}

	ans += t;
// 	t = 0;
	if (xx + 1 <= yy - 1)
		for (int i = xx + 1; i <= yy - 1; i ++) {
			ans += abs(c[i]);
		}
//
	t = 0;
	if (yy <= n)
		for (int i = yy + 1; i <= n; i ++) {
			t = max(t, s[yy - 1] - s[i - 1] + c[i]);
		}

	ans += t;

	return ans;
}
signed main() {
	int t;
	cin >> t;
	while (t --) {
//		f = f1 = 0;
//		ans
		cin >> n;
		for (int i = 1; i <= n; i++) cin >> r;
//		for (int i = 1; i <= n; i++) {
		inint();
// 			if(n <= 8) {ans = solve();}
		if (!f) {
			ans = fu();
		} else if (!f1) {
			ans = zheng();
		} else {
			ans = zero();
		}
//			cout << ans << endl;
//		}
//		for(int i = 1; i <= n; i++) {
//		if (f)
//			ans = fu();
//		if (f1) ans = zheng();
//		else ans = zero();
////			cout << ans
//		}
		cout << ans << endl;
	}
	return 0;
}