189A - Cut Ribbon - CodeForces Solution

#include<bits/stdc++.h>
#define ll long long
#define pb push_back
#define fr(a,b) for(int i = a; i < b; i++)
#define frr(a,b) for(int i = a; i >= b; i--)
#define rep(i,a,b) for(int i = a; i < b; i++)
#define mod 1000000007
#define inf (1LL<<60)
#define all(x) (x).begin(), (x).end()
#define triplet pair<ll,pair<ll,ll>>
#define fast_io ios_base::sync_with_stdio(false);cin.tie(NULL)
#define precise(x,y) cout<<fixed<<setprecision(y)<<x
using namespace std;
int M = 1e9 + 7;

int solve(int i, int target, vector<int>& v, vector<vector<int>>& dp){
    if(target==0) return 0;
    if(i<0) return INT_MIN;
    if(dp[i][target]!=-1) return dp[i][target];
    int not_take =  solve(i-1,target,v,dp);
    int take = INT_MIN;
    if(target-v[i]>=0) take =  1 + solve(i,target-v[i],v,dp);
    return dp[i][target] = max(take,not_take);
}

int main(){
    int n;
    cin>>n;
    vector<int> v(3);
    fr(0,3) cin>>v[i];
    vector<vector<int>> dp(3,vector<int>(n+1,-1));
    int ans = solve(2,n,v,dp);
    cout<<ans<<"\n";
    return 0;
}