Create two_sum_problem.cpp

hashing/two_sum_problem.cpp

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+// C++ program to check if given array
+// has 2 elements whose sum is equal
+// to the given value using hashing technique
+#include <bits/stdc++.h>
+ 
+using namespace std;
+ 
+void print_pairs(int arr[], int arr_size, int sum)
+{
+    unordered_set<int> s;
+    for (int i = 0; i < arr_size; i++) {
+        int temp = sum - arr[i];
+ 
+        if (s.find(temp) != s.end()) {
+            cout << "Yes" << endl;
+            return;
+        }
+        s.insert(arr[i]);
+    }
+    cout << "No" << endl;
+}
+ 
+/* Driver Code */
+int main()
+{
+    int A[] = { 1, 4, 45, 6, 10, 8 };
+    int n = 16;
+    int arr_size = sizeof(A) / sizeof(A[0]);
+ 
+    // Function calling
+    print_pairs(A, arr_size, n);
+ 
+    return 0;
+}
+
+// Input: arr[] = {1, -2, 1, 0, 5}, x = 0
+// Output: No