title: Sum Pairwise Products 1
signature: function sumPairwiseProducts1($n) {
test_code: <?php
  
  
  // SOLUTION CODE 
  // ============================================
  PLACEHOLDER_CODE_BODY
  
  // TESTING CODE 
  // ============================================
  function validateSolution($actual, $expected){
      return serialize($actual) == serialize($expected);
  }
  
  function driver($n, $expected){
      try{
        if (validateSolution(PLACEHOLDER_FN_NAME($n), $expected)){
          return "PASSED";
        }
        return "FAILED";
      }
      catch (Exception $exception_obj) {
        return get_class($exception_obj);
      }
  }
  
  function main(){
      printf("TEST-0...%s\n",driver(
        41, 
        382571));
      
      printf("TEST-1...%s\n",driver(
        50, 
        834275));
      
      printf("TEST-2...%s\n",driver(
        67, 
        2645897));
      
      printf("TEST-3...%s\n",driver(
        18, 
        15675));
      
      printf("TEST-4...%s\n",driver(
        60, 
        1711355));
      
      printf("TEST-5...%s\n",driver(
        6, 
        266));
      
      printf("TEST-6...%s\n",driver(
        27, 
        74907));
      
      printf("TEST-7...%s\n",driver(
        46, 
        601036));
      
      printf("TEST-8...%s\n",driver(
        50, 
        834275));
      
      printf("TEST-9...%s\n",driver(
        20, 
        23485));
      
  }
  
  main();
  ?>
source_py: def sum_pairwise_products_1(n):
      multiTerms = ((n * (n + 1)) // 2)
      sm = multiTerms
      for i in range(2, (n + 1)):
          multiTerms = (multiTerms - (i - 1))
          sm = (sm + (multiTerms * i))
      return sm
source_cpp: long long int sum_pairwise_products_1(int n) {
    long long int multiTerms = n * ( n + 1 ) / 2;
    long long int sum = multiTerms;
    for ( int i = 2;
    i <= n;
    i ++ ) {
      multiTerms = multiTerms - ( i - 1 );
      sum = sum + multiTerms * i;
    }
    return sum;
  }