knapsack in cryptography code example
Example 1: knapsack problem
#include <bits/stdc++.h>
using namespace std;
int n, w;
int main() {
cin >> n >> w;
vector<long long> dp(w + 1, 0);
for (int i = 0; i < n; ++i) {
int value, cost;
cin >> value >> cost;
for (int j = w; j >= cost; --j)
dp[j] = max(dp[j], value + dp[j - cost]);
}
cout << dp[w];
}
Example 2: knapsack
#include<bits/stdc++.h>
using namespace std;
vector<pair<int,int> >a;
int n,s,dp[1002][1002];
void ini(){
for(int i=0;i<1002;i++)
for(int j=0;j<1002;j++)
dp[i][j]=-1;
}
int f(int x,int b){
if(x>=n or b<=0)return 0;
if(dp[x][b]!=-1)return dp[x][b];
return dp[x][b]=max(f(x+1,b),b-a[x].second>=0?f(x+1,b-a[x].second)+a[x].first:INT_MIN);
}
int main(){
ios_base::sync_with_stdio(0);cin.tie(0);
cin>>n>>s;
a.resize(n);
for(int i=0;i<n;i++)
cin>>a[i].first;
for(int i=0;i<n;i++)
cin>>a[i].second;
ini();
cout<<f(0,s);
return 0;
}