/*
 * @lc app=leetcode id=1234 lang=rust
 *
 * [1234] Replace the Substring for Balanced String
 *
 * https://leetcode.com/problems/replace-the-substring-for-balanced-string/description/
 *
 * algorithms
 * Medium (31.48%)
 * Total Accepted:    7.7K
 * Total Submissions: 24.5K
 * Testcase Example:  '"QWER"'
 *
 * You are given a string containing only 4 kinds of characters 'Q', 'W', 'E'
 * and 'R'.
 * 
 * A string is said to be balanced if each of its characters appears n/4 times
 * where n is the length of the string.
 * 
 * Return the minimum length of the substring that can be replaced with any
 * other string of the same length to make the original string s balanced.
 * 
 * Return 0 if the string is already balanced.
 * 
 * 
 * Example 1:
 * 
 * 
 * Input: s = "QWER"
 * Output: 0
 * Explanation: s is already balanced.
 * 
 * Example 2:
 * 
 * 
 * Input: s = "QQWE"
 * Output: 1
 * Explanation: We need to replace a 'Q' to 'R', so that "RQWE" (or "QRWE") is
 * balanced.
 * 
 * 
 * Example 3:
 * 
 * 
 * Input: s = "QQQW"
 * Output: 2
 * Explanation: We can replace the first "QQ" to "ER". 
 * 
 * 
 * Example 4:
 * 
 * 
 * Input: s = "QQQQ"
 * Output: 3
 * Explanation: We can replace the last 3 'Q' to make s = "QWER".
 * 
 * 
 * 
 * Constraints:
 * 
 * 
 * 1 <= s.length <= 10^5
 * s.length is a multiple of 4
 * s contains only 'Q', 'W', 'E' and 'R'.
 * 
 * 
 */
impl Solution {
    pub fn balanced_string(s: String) -> i32 {
        
    }
}


pub struct Solution; 

use std::collections::HashMap;
use std::collections::HashSet;
use std::fmt::Debug;
use std::hash::Hash;
use std::iter::FromIterator;
// use std::collections::VecDeque; 
// use std::collections::BTreeMap; 

#[allow(dead_code)]
pub fn print_map<K: Debug + Eq + Hash, V: Debug>(map: &HashMap<K, V>) {
    for (k, v) in map.iter() {
        println!("{:?}: {:?}", k, v);
    }
}

#[allow(dead_code)]
pub fn say_vec(nums: Vec<i32>){
	println!("{:?}", nums);
}

#[allow(dead_code)]
pub fn char_frequency(s: String) -> HashMap<char, i32> {
    let mut res:HashMap<char, i32> = HashMap::new(); 
    for c in s.chars(){
        *res.entry(c).or_insert(0) += 1;
    }
    res 
}

#[allow(dead_code)]
pub fn vec_counter(arr: Vec<i32>) -> HashMap<i32, i32> {
    let mut c = HashMap::new(); 
    for n in arr { *c.entry(n).or_insert(0) += 1; }
    c 
}

#[allow(dead_code)]
pub fn vec_to_hashset(arr: Vec<i32>) -> HashSet<i32> {
   HashSet::from_iter(arr.iter().cloned())
}

#[allow(dead_code)]
pub fn int_to_char(n: i32) -> char {
    // Convert number 0 to a, 1 to b, ...
    assert!(n >= 0 && n <= 25);
    (n as u8 + 'a' as u8) as char
}

#[allow(dead_code)]
fn sayi32(i: i32) {
	println!("{}", i);
}

#[allow(dead_code)]
fn sayi32_arr(arr: &Vec<i32>) {
	println!("{:?}", arr);
}

#[allow(dead_code)]
pub fn bisect_left(arr: &Vec<i32>, target: i32) -> usize {
    let (mut lo, mut hi) = (0, arr.len() - 1);
    let mut mid;
    while lo < hi {
        mid = (lo + hi) >> 1; 
        if arr[mid as usize] >= target { hi = mid; }
        else { lo = mid + 1; }
    }
    lo 
 }

 #[allow(dead_code)]
pub fn bisect_right(arr: &Vec<i32>, target: i32) -> usize {
    let (mut lo, mut hi) = (0, arr.len() - 1);
    let mut mid;
    while lo < hi {
        mid = (lo + hi + 1) >> 1; 
        if arr[mid as usize] > target { hi = mid - 1; }
        else { lo = mid; }
    }
    if arr[hi] > target { hi } else {hi + 1}
}