rod cutting problem

#pragma GCC optimize ("O3")
#pragma GCC target ("sse4")

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<string,int> psi;
typedef priority_queue<int> pqmax;
typedef priority_queue<int,vector<int>,greater<int>> pqmin;
typedef unordered_map<int,int> mii;
typedef unordered_map<long long,long long> mll;
typedef unordered_map<string,int> msi;
typedef unordered_map<char,int> mci;
typedef unordered_set<int> si;
typedef unordered_set<long long> sll;
typedef unordered_set<string> ss;
typedef unordered_set<char> sc;
typedef map<int,int> ormii;
typedef map<long long,long long> ormll;
typedef map<string,int> ormsi;
typedef map<char,int> ormci;
typedef set<int> orsi;
typedef set<long long> orsll;
typedef set<string> orss;
typedef set<char> orsc;
typedef vector<int> vi;
typedef vector<string> vs;
typedef vector<char> vc;
typedef vector<ll> vll;
typedef vector<vector<int>> vvi;
typedef vector<vector<string>> vvs;
typedef vector<vector<ll>> vvll;

#define FOR(i, a, b) for (auto i=a; i<=(b); i++)
#define FORd(i,b,a) for (int i =b; i >= a; i--)
#define sortinc(v)  sort(v.begin(),v.end())
#define sortdec(v)  sort(v.rbegin(),v.rend())
#define sz(x) (int)(x).size()
#define mp make_pair
#define pb push_back
#define pob pop_back
#define pf push_front
#define pof pop_front
#define fi first
#define se second
#define ins insert

const int MOD = 1000000007;
int m(ll k) {return k%MOD;}
//type functions here
/*ROD cutting problem given a rod of length n ,with array B of prices from 1 to n when you are  cutting
a length x (x E 1 to n)  your profit will be B[x-1] the goal is to find out the max profit for the given n length rod
 */


int cut_rod(int len,vi &B)
{
   vvi dp(len+1,vi(len+1,0));
   FOR(i,0,len) dp[0][i]=0;
   FOR(i,0,len) dp[i][0]=0;
   FOR(i,1,len)
   {
       FOR(j,1,len)
     {
     if(i<=j)
     dp[i][j]=max(dp[i][j-i]+B[i-1],dp[i-1][j]);
     else
       dp[i][j]=dp[i-1][j];
    }
   }

    return dp[len][len];
}
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    int tc=1;
    //cin>>tc;
    FOR(w,1,tc)
    {
       vi B={4,5,1,0};
       cout<<cut_rod(sz(B),B)<<endl;
    }
    return 0;
}