New Commit

Author: coder-mayank22

01_Knapsack.c

@@ -2,9 +2,7 @@
 
 int max(int a, int b) { return (a > b) ? a : b; }
 
-// Returns the maximum value that
-// can be put in a knapsack of capacity W
-int knapSack(int W, int wt[], int val[], int n)
+int knapSack(int W, int wt[], int pt[], int n, int solutionVector[n])
 {
     int i, w;
     int K[n + 1][W + 1];
@@ -15,28 +13,48 @@ int knapSack(int W, int wt[], int val[], int n)
             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][w] = max(pt[i - 1] + K[i - 1][w - wt[i - 1]],
                               K[i - 1][w]);
             else
                 K[i][w] = K[i - 1][w];
         }
     }
 
+    // To get the solution vector
+    int count = 0, flag, base = K[n][W];
+
+    for(i=n;i>0;i--){
+        int j = i-1;
+        base = base - count;
+        flag=0;
+        // Checks if the weight is unique for the given value of i
+        for(w = 0; w<=W; w++){
+            if(K[j][w] == base){
+                solutionVector[i-1] = 0;
+                count = 0;
+                flag = 1;
+                break;
+            }
+        }
+        if(flag == 1) // Not unique (determined from above)
+            continue;
+        else{
+            solutionVector[i-1] = 1;
+            count = pt[i-1];
+        }
+    }
+
     return K[n][W];
 }
 
 // Driver Code
 int main()
 {
-    /*int profit[] = { 60, 100, 120 };
-    int weight[] = { 10, 20, 30 };
-    int W = 50;*/
     int i, n;
     printf("Enter number of items: ");
     scanf("%d", &n);
 
-    int profit[n], weight[n], W;
+    int profit[n], weight[n], W, solutionVector[n];
     printf("Enter the profits and weights:\n");
     for(i=0;i<n;i++){
         printf("Item %d\n", i+1);
@@ -47,9 +65,18 @@ int main()
         printf("\n");
     }
 
-    printf("Enter the capacity of the Knapsack: ");
+    printf("Profits and their weights:\n\n");
+    for(i=0;i<n;i++){
+        printf("p[%d] = %d\tw[%d] = %d\n", i, profit[i], i, weight[i]);
+    }
+
+    printf("\nEnter the capacity of the Knapsack: ");
     scanf("%d", &W);
 
-    printf("Profit: %d", knapSack(W, weight, profit, n));
+    int max_profit = knapSack(W, weight, profit, n, solutionVector);
+    printf("Solution Vector: ");
+    for(i = 0; i < n; i++) printf("%d ", solutionVector[i]);
+
+    printf("\nMaximum Profit: %d\n", max_profit);
     return 0;
 }