※ 引述《sustainer123 (caster )》之铭言：
: 1051. Height Checker
: 给定一数列heights 我们期待heights是一非递减数列
: 看解答好像能把时间复杂度降到n 等等研究一下
思路:
用bucket
然后这题用HashMap没特别省时间
还会耗空间资源
这种小范围的还是直接用Vec比较好
但我都写了
:(
Code:
use std::collections::HashMap;
impl Solution {
pub fn height_checker(heights: Vec<i32>) -> i32 {
let mut heights_freq= HashMap::new();
for &num in &heights {
*heights_freq.entry(num).or_insert(0) += 1;
}
let mut index = 0;
let mut result = 0;
for height in 0..=100 {
if let Some(&count) = heights_freq.get(&(height as i32)) {
for _ in 0..count {
if heights[index] != height as i32 {
result +=1;
}
index += 1;
}
}
}
result
}
}