chore(CPlusPlus): add fractional-knapsack (#332)

algorithms/CPlusPlus/Arrays/fractional-knapsack.cpp

@@ -0,0 +1,69 @@
+// Description : Given weights and values of n items, put these items in a knapsack of capacity W to get the maximum total value in the knapsack.
+// We can break items for maximizing the total value of knapsack/
+
+// Algorithm Type: Divide & Conquer
+// Time Complexity: O(n*log(n))
+#include <bits/stdc++.h>
+using namespace std;
+struct Item
+{
+    int value, weight;
+};
+bool comp(Item a, Item b)
+{
+    double r1 = (double)a.value / (double)a.weight;
+    double r2 = (double)b.value / (double)b.weight;
+    return r1 > r2;
+}
+
+//Function to get the maximum total value in the knapsack.
+double fractionalKnapsack(int W, vector<Item> &arr, int n)
+{
+
+    sort(arr.begin(), arr.end(), comp);
+
+    int curWeight = 0;
+    double finalvalue = 0.0;
+
+    for (int i = 0; i < n; i++)
+    {
+
+        if (curWeight + arr[i].weight <= W)
+        {
+            curWeight += arr[i].weight;
+            finalvalue += arr[i].value;
+        }
+
+        else
+        {
+            int remain = W - curWeight;
+            finalvalue += (arr[i].value / (double)arr[i].weight) * (double)remain;
+            break;
+        }
+    }
+
+    return finalvalue;
+}
+int main()
+{
+    int W; //    Weight of knapsack
+    cout << "Enter the weight(W) of the knapsack" << endl;
+    cin >> W;
+    int n;
+    cout << "Enter the total number(n) of {Value-Weight}pairs" << endl;
+    cin >> n;
+    vector<Item> arr(n);
+
+    for (int i = 0; i < n; i++)
+    {
+
+        cout << "Enter value for pair " << i + 1 << endl;
+        cin >> arr[i].value;
+        cout << "Enter weight for pair " << i + 1 << endl;
+        cin >> arr[i].weight;
+    }
+
+    // Function call
+    cout << "Maximum value we can obtain = " << fractionalKnapsack(W, arr, n);
+    return 0;
+}

algorithms/CPlusPlus/README.md

@@ -9,6 +9,7 @@
 6. [Boyer–Moore Voting Algorithm](Arrays/boyer_more.cpp)
 7. [Reverse Array](Arrays/reverse-array.cpp)
 8. [Sorted-Rotated Search Array](Arrays/search-sorted-rotated.cpp)
+9. [Fractional Knapsack](Arrays/fractional-knapsack.cpp)
 
 ## Graphs
 1. [Bellman Ford Algorithm](Graphs/bellmam-ford.cpp)