title: Find The Number Occurring Odd Number Of Times
signature: pub fn find_the_number_occurring_odd_number_of_times(arr: Vec<i32>, arr_size: i32) -> i32 {
test_code: use std::collections::HashMap;
  use std::collections::HashSet;
  use std::cmp::*;
  use std::collections::*;
  use std::fmt::*; 
  
  
  // SOLUTION CODE
  // ============================================
  PLACEHOLDER_CODE_BODY
  
  // TESTING CODE 
  // ============================================
  pub fn validate_solution(actual: i32, expected: i32)->bool{
  return actual==expected
  }
  pub fn driver(arr: Vec<i32>, arr_size: i32, expected: i32)->String{
      if validate_solution(PLACEHOLDER_FN_NAME(arr, arr_size), expected) {
        return "PASSED".to_string();
      };
      return "FAILED".to_string();
  
  }
  
  fn main() {
      println!("TEST-0...{}", driver(
        Vec::from([1, 5, 5, 8, 14, 15, 17, 17, 18, 23, 23, 25, 26, 35, 36, 39, 51, 53, 56, 56, 60, 62, 64, 64, 65, 66, 67, 68, 71, 75, 80, 82, 83, 88, 89, 91, 91, 92, 93, 95, 99]), 31, 
        1
      ));
      
      println!("TEST-1...{}", driver(
        Vec::from([-56, 98, 44, 30, -88, 18, 60, 86, 4, 16, 10, 64, -22, -86, -66, -16, 70, -44, 98, 78, -96, -66, 92, 10, 40, -16]), 19, 
        -56
      ));
      
      println!("TEST-2...{}", driver(
        Vec::from([0, 0, 0, 0, 0, 1, 1, 1]), 6, 
        0
      ));
      
      println!("TEST-3...{}", driver(
        Vec::from([36, 11, 83, 41, 42, 14, 46, 89, 91, 96, 57, 42, 74, 73, 9, 26, 79, 40, 31, 69, 44, 39, 14, 92, 34, 20, 52, 47, 14]), 25, 
        36
      ));
      
      println!("TEST-4...{}", driver(
        Vec::from([-84, -84, -84, -78, -66, -62, -62, -36, -24, -10, -10, -8, -4, -2, 12, 14, 20, 22, 36, 42, 46, 66, 84, 96, 96, 98]), 23, 
        -84
      ));
      
      println!("TEST-5...{}", driver(
        Vec::from([1, 1, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1]), 19, 
        1
      ));
      
      println!("TEST-6...{}", driver(
        Vec::from([11, 12, 14, 28, 42, 48, 50, 58, 67, 74, 86, 89, 95]), 7, 
        11
      ));
      
      println!("TEST-7...{}", driver(
        Vec::from([52, -56, -6, 74, 10, 68, 74, 10, 16, -80, 82, -32, 6, -6, 82, 20]), 11, 
        52
      ));
      
      println!("TEST-8...{}", driver(
        Vec::from([0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1]), 31, 
        0
      ));
      
      println!("TEST-9...{}", driver(
        Vec::from([4, 80, 92]), 1, 
        4
      ));
      
  }
source_py: def find_the_number_occurring_odd_number_of_times(arr, arr_size):
      for i in range(0, arr_size):
          count = 0
          for j in range(0, arr_size):
              if (arr[i] == arr[j]):
                  count += 1
          if ((count % 2) != 0):
              return arr[i]
      return (- 1)
source_cpp: int find_the_number_occurring_odd_number_of_times(vector<int> arr, int arr_size) {
    for ( int i = 0;
    i < arr_size;
    i ++ ) {
      int count = 0;
      for ( int j = 0;
      j < arr_size;
      j ++ ) {
        if ( arr [ i ] == arr [ j ] ) count ++;
      }
      if ( count % 2 != 0 ) return arr [ i ];
    }
    return - 1;
  }