I am not able to solve cses book shop problem using recursive method as i am getting TLE. I am not that good in iterative method can somebody tell me what is wrong and how to prevent it. Below is my code

#include <bits/stdc++.h>

int n , x;
int h[1001] , s[1001];
const int mxn = 1e5 + 1;
int dp[1001][mxn];

int rec(int lvl ,int capa) {
	if (lvl == n) return 0;
	if (capa > x) return 0;
	if(dp[lvl][capa] != -1) return dp[lvl][capa];
	int ans {};
 	ans = rec(lvl + 1, capa);
	
	// ans = INT_MIN;
	if (capa + h[lvl] <= x) {
		ans = std::max(ans , s[lvl] + rec(lvl + 1, capa + h[lvl]));
	}
	return dp[lvl][capa] = ans;
}
 
int main() {
	std::cin >> n >> x;
	memset(dp,-1,sizeof(dp));
	for (int i = 0 ; i < n ; i++) {
		std::cin >> h[i];
	}
	for (int i = 0 ; i < n ;i++) {
		std::cin >> s[i];
	}
	std::cout << rec(0,0);
	return 0;	
}

will i be able to grow in codeforces if i solve usaco bronze or silver problems everyday? Should i solve them ? are there any resources to prepare for ioi other than codeforces and atcoder ?