Missing Number (Math, bit manipulation)

C++/1235.cpp

@@ -0,0 +1,24 @@
+// Missing Number (Math, bit manipulation)
+
+
+#include <bits/stdc++.h>
+using namespace std;
+
+// Function to get the missing number
+int getMissingNo(int a[], int n)
+{
+
+    int total = (n + 1) * (n + 2) / 2;
+    for (int i = 0; i < n; i++)
+        total -= a[i];
+    return total;
+}
+
+// Driver Code
+int main()
+{
+    int arr[] = { 1, 2, 4, 5, 6 };
+    int n = sizeof(arr) / sizeof(arr[0]);
+    int miss = getMissingNo(arr, n);
+    cout << miss;
+}

C++/1395.cpp

@@ -0,0 +1,21 @@
+#Count Negative Numbers in a Column-Wise and Row-Wise Sorted Matrix
+
+int countNegative(int M[][4], int n, int m) 
+{ 
+    int count = 0; 
+
+    // Follow the path shown using 
+    // arrows above 
+    for (int i = 0; i < n; i++) { 
+        for (int j = 0; j < m; j++) { 
+            if (M[i][j] < 0) 
+                count += 1; 
+
+            // no more negative numbers 
+            // in this row 
+            else
+                break; 
+        } 
+    } 
+    return count; 
+}