added code of knapsack

Algorithms/Dynamic Programming/C++/knapsack.cpp

@@ -0,0 +1,43 @@
+#include <bits/stdc++.h>
+using namespace std;
+#define ll long long
+#define o 100005
+#define MOD 1000000007
+#define pb push_back
+#define mp make_pair
+#define mem(a,b) memset(a,(b),sizeof(a))
+#define lpo(a) for(int i=0;i<a;i++)
+#define loop(a,x) for(int i=a;i<x;i++)
+#define srt(x) sort(x.begin(),x.end())
+#define all(x) x.begin(),x.end()
+const ll MAX=1000000000000000001;
+typedef pair<int,int> pii;
+int knapSack(int W, int wt[], int val[], int n) 
+{ 
+   int i, w; 
+   int K[n+1][W+1]; 
+   for (i = 0; i <= n; i++) 
+   { 
+       for (w = 0; w <= W; w++) 
+       { 
+           if (i==0 || w==0) 
+               K[i][w] = 0; 
+           else if (wt[i-1] <= w) 
+                 K[i][w] = max(val[i-1] + K[i-1][w-wt[i-1]],  K[i-1][w]); 
+           else
+                 K[i][w] = K[i-1][w]; 
+       } 
+   } 
+
+   return K[n][W]; 
+} 
+
+int main() 
+{ 
+    int val[] = {20, 30, 40}; 
+    int wt[] = {10, 20, 30}; 
+    int  W = 50; 
+    int n = sizeof(val)/sizeof(val[0]); 
+    cout<<knapSack(W, wt, val, n); 
+    return 0; 
+}