title: Lower Insertion Point
signature: pub fn lower_insertion_point(arr: Vec<i32>, n: i32, x: 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>, n: i32, x: i32, expected: i32)->String{
      if validate_solution(PLACEHOLDER_FN_NAME(arr, n, x), expected) {
        return "PASSED".to_string();
      };
      return "FAILED".to_string();
  
  }
  
  fn main() {
      println!("TEST-0...{}", driver(
        Vec::from([1, 2, 5, 5, 16, 16, 20, 26, 32, 35, 39, 39, 41, 44, 48, 48, 51, 59, 59, 62, 66, 66, 70, 74, 75, 78, 80, 86, 86, 96]), 17, 29, 
        8
      ));
      
      println!("TEST-1...{}", driver(
        Vec::from([-76, 80, -6, -2, 50, 72, 84, -56, 70, 8, 48, 6, -24, -50, -72]), 14, 9, 
        14
      ));
      
      println!("TEST-2...{}", driver(
        Vec::from([0, 0, 0, 0, 0, 1, 1, 1, 1]), 8, 4, 
        8
      ));
      
      println!("TEST-3...{}", driver(
        Vec::from([74, 65, 84, 71]), 2, 3, 
        0
      ));
      
      println!("TEST-4...{}", driver(
        Vec::from([-96, -92, -90, -86, -84, -76, -76, -62, -58, -54, -50, -50, -44, -42, -38, -34, -14, -8, 6, 12, 24, 38, 40, 50, 62, 84, 86, 92]), 19, 19, 
        19
      ));
      
      println!("TEST-5...{}", driver(
        Vec::from([1, 1, 0, 0, 0, 1, 1, 1, 0, 0, 1, 1, 0, 1, 0, 1, 0, 0, 0, 1, 1, 1, 1]), 12, 17, 
        12
      ));
      
      println!("TEST-6...{}", driver(
        Vec::from([6, 10, 14, 14, 16, 19, 23, 23, 25, 26, 29, 34, 42, 42, 43, 45, 47, 49, 50, 51, 51, 56, 59, 65, 69, 72, 75, 78, 79, 80, 82, 82, 82, 84, 85, 91, 98]), 31, 24, 
        8
      ));
      
      println!("TEST-7...{}", driver(
        Vec::from([-90, -2, 22, -2, 58, -2, 96, 38, 36, -66, -98, 22, -80, -32, 22, 0, -34, -16, 82, 76, 12, 84, 66, 8, 32, 18, -98, -10]), 22, 16, 
        2
      ));
      
      println!("TEST-8...{}", driver(
        Vec::from([0, 0, 0, 1, 1, 1, 1]), 3, 5, 
        3
      ));
      
      println!("TEST-9...{}", driver(
        Vec::from([85, 59, 22, 52, 93, 14, 42, 71, 69, 15, 52, 78, 35, 61, 92, 90, 70, 48, 47, 72, 74, 46, 22, 74, 83, 32, 14, 24, 18, 27, 18, 68, 29, 31]), 19, 33, 
        0
      ));
      
  }
source_py: def lower_insertion_point(arr, n, X):
      if (X < arr[0]):
          return 0
      elif (X > arr[(n - 1)]):
          return n
      lowerPnt = 0
      i = 1
      while ((i < n) and (arr[i] < X)):
          lowerPnt = i
          i = (i * 2)
      while ((lowerPnt < n) and (arr[lowerPnt] < X)):
          lowerPnt += 1
      return lowerPnt
source_cpp: int lower_insertion_point(vector<int> arr, int n, int X) {
    if ( X < arr [ 0 ] ) return 0;
    else if ( X > arr [ n - 1 ] ) return n;
    int lowerPnt = 0;
    int i = 1;
    while ( i < n && arr [ i ] < X ) {
      lowerPnt = i;
      i = i * 2;
    }
    while ( lowerPnt < n && arr [ lowerPnt ] < X ) lowerPnt ++;
    return lowerPnt;
  }