Dynamic programming: grouping knapsack problem

ACwing 9.

and 01 Backpacks are similar

#include <iostream>
using namespace std;

const int N=110;
int f[N][N];  // Only once i Select from a group of items , The current volume is less than or equal to j The maximum of 
int v[N][N],w[N][N],s[N];   //v Is the volume ,w For value ,s On behalf of the i Number of items in the group 
int n,m,k;

int main(){
    cin>>n>>m;
    for(int i=1;i<=n;i++){
        cin>>s[i];
        for(int j=0;j<s[i];j++){
            cin>>v[i][j]>>w[i][j];  // Read in 
        }
    }

    for(int i=1;i<=n;i++){
        for(int j=1;j<=m;j++){
            f[i][j]=f[i-1][j];  // No election 
            for(int k=0;k<s[i];k++){
                if(j>=v[i][k])     f[i][j]=max(f[i][j],f[i-1][j-v[i][k]]+w[i][k]);  
            }
        }
    }
    cout<<f[n][m]<<endl;
}

Optimize ：

#include <iostream>
using namespace std;

const int N=110;
int f[N];  // Only once i Select from a group of items , The current volume is less than or equal to j The maximum of 
int v[N][N],w[N][N],s[N];   //v Is the volume ,w For value ,s On behalf of the i Number of items in the group 
int n,m,k;

int main(){
    cin>>n>>m;
    for(int i=1;i<=n;i++){
        cin>>s[i];
        for(int j=0;j<s[i];j++){
            cin>>v[i][j]>>w[i][j];  // Read in 
        }
    }

    for(int i=1;i<=n;i++){
        for(int j=m;j>=0;j--){
            for(int k=0;k<s[i];k++){
                if(j>=v[i][k])  f[j]=max(f[j],f[j-v[i][k]]+w[i][k]);  
            }
        }
    }
    cout<<f[m]<<endl;
}