题目点这！！！！
/*01背包还可以这样用，长见识了对于w[i] > 0 和 w[i] <= 0两种情况分开讨论滚动数组来理解注意w[i] <= 0 的数组边界问题还有一点是坐标偏移以正的代表负的，这样就可以限定很多条件这些条件就可以应用到题目中去了选与不选这不就是01背包问题吗*/
#include <iostream>
#include <cstring>
using namespace std;
const int M = 2e5 + 10;
const int node = 1e5;
int n;
int dp[M];void bag01(int v, int w)
{if (w > 0) {for (int i = M; i >= w; --i){dp[i] = max(dp[i], dp[i - w] + v);}}else{for (int i = 0; i < M + w; ++i){dp[i] = max(dp[i], dp[i - w] + v);}}
}int main()
{ios::sync_with_stdio(false);cin.tie(0), cout.tie(0);cin >> n;memset(dp, -0x3f3f3f3f, sizeof dp);dp[node] = 0;for (int i = 1; i <= n; ++i){int w, v;cin >> w >> v;bag01(v, w);}int ans = 0;for (int i = node; i <= M; ++i){if (dp[i] > 0) ans = max(ans, dp[i] + i - node);}if (ans >= 0)cout << ans << endl;else cout << "0" << endl; return 0;
}