added test file and executable. not working, returns true all the time, and takes 1 less input line than it should

q5/q5a.cpp

@@ -0,0 +1,111 @@
+#include <iostream>
+#include <algorithm>
+#include <cstdlib>
+#include <string>
+#include <sstream>
+
+/*int n;
+int twon = 2 * n;
+int * a;
+int * b;
+int * sums = malloc(2 * sizeof(b));
+int pos = 0;
+
+for (int i = 0; i < twon; i++)
+
+{
+    for (int j = (i + 1); j < twon; j++, pos++)
+    
+    {
+        sums[pos] = b[i] + b[j];
+    }
+}
+
+sort c;
+
+for (int i = 0; i < twon; i++)
+
+{
+    for (int j = (i + 1); j < twon; j++, pos++)
+    
+    {
+        if sums.search(a[i] + a[j]) return true;
+    }
+}
+
+return false;
+
+================*/
+int main()
+{
+    int n;
+    std::cin >> n; // get the length of the array we are manipulating
+    std::cout << n << std::endl;
+
+    int * a = (int *) malloc(n * sizeof(int));
+    int * b = (int *) malloc(n * sizeof(int));
+    
+    for (int i = 0; i < n; ++i)
+    {
+        // get each line which is 2 ints, put into A and B
+        std::string input;
+        std::getline(std::cin, input);
+        std::stringstream nums(input);
+        //input >> nums;
+        
+        nums >> a[i];
+        nums >> b[i];
+    }
+    
+    /*
+    int clen = 2 * n;
+    int * C = malloc(clen * sizeof(int)); // to hold the list of possible sums
+    int tempcount = 0;
+    
+    for (int i = 0; i < n; i++)
+    
+    {
+        for (int j = (i + 1); j < n; ++j, ++tempcount)
+        
+        {
+            C[tempcount] = (B[i] + B[j]);
+            C[clen - tempcount - 1] = (A[i] + A[j]);
+        }
+    } // n squared
+    
+    sort(C, C + clen); // n^2 log n squared == n^2 log n */
+    
+    int clen = (n * (n - 1)) / 2; // total possible sums in an array of length n
+    int * c = (int *) malloc(clen * sizeof(int));
+    int tempcount = 0;
+    
+    // Store within c the possible sums inside b
+    for (int i = 0; i < n; ++i)
+    {
+        for (int j = (i + 1); j < n; ++j, ++tempcount)
+        {
+            c[tempcount] = b[i] + b[j];
+        }
+    }
+    
+    // sort c, with time complexity n squared log (n squared), which reduces to n squared log n
+    std::sort(c, c + clen);
+    
+    // for reach sum in a, see if it is in c. n squared checks of log (n squared), or n squared log n
+    for (int i = 0; i < clen; ++i)
+    {
+        for (int j = (i + 1); j < n; ++j)
+        {
+            if (std::binary_search(c, (c + clen), (a[i] + a[j])))
+            {
+                free(a); free (b); free(c);
+		std::cout << 1 << std::endl;
+                return true;
+            }
+        }
+    }
+    
+    free(a); free(b); free(c);
+    std::cout << 0 << std::endl;
+    return false;
+}