如图，看完题目知道是dp，还是没想出来怎么写（因为条件较多）。

先贴题解，留待复习。

#include<cstdio>
#include<iostream>
#include<cstring>
#include<algorithm>
using namespace std;
typedef long long ll;
const int maxn = 110;
const int inf = 1e9;
ll dp[maxn][maxn];
ll a[maxn], b[maxn], c[maxn];
int n, m;
int T;

int main()
{
    scanf("%d", &T);
    while(T--)
    {
        cin >> n >> m;
        for(int i = 1; i <= n; i++)
        {
            cin >> a[i] >> b[i] >> c[i];
        }

        for(int i = 1; i <= n; i++)
        {
            for(int j = 1; j <= i; j++)
                dp[i][j] = -inf;
        }
        dp[0][0] = m;
        c[0]= 0;
        for(int i = 1; i <= n; i++)
        {
            for(int j = 0; j <= i; j++)
            {
                ll go = -inf;
                if(j != 0 && min(c[i - 1] + dp[i - 1][j - 1], b[i]) > a[i])
                {
                    go = min(c[i - 1] + dp[i - 1][j - 1], b[i]) - a[i];
                }
                dp[i][j] = max(dp[i - 1][j] + c[i - 1], go);
            }
        }

        for(int i = n; i >= 1; i--)
        {
            if(dp[n][i] > 0)
            {
                cout << i << endl;
                break;
            }
        }
    }
    return 0;
}