2023-01-06：给定一个只由小写字母组成的字符串 str，长度为 N， 给定一个只由 0、1 组成的数组 arr，长度为 N， arr[i] == 0 表示 str 中 i 位置的字符不许修改， arr[i] ==

use rand::Rng;use std::{iter::repeat, vec};fn main() {    let str = "bbbcdbcade";    let mut arr = vec![1, 1, 0, 1, 0, 1, 0, 0, 1, 0];    let m = 4;    let ans = max_len2(&str, &mut arr, m);    println!("ans = {}", ans);    let nn: i32 = 100;    let rr: i32 = 5;    let test_time: i32 = 5000;    println!("测试开始");    for i in 0..test_time {        let n = rand::thread_rng().gen_range(0, nn) + 1;        let m = rand::thread_rng().gen_range(0, n) + 1;        let str = random_string(n, rr);        let mut arr = random_array(n);        let ans1 = max_len1(&str, &mut arr, m);        let ans2 = max_len2(&str, &mut arr, m);        if ans1 != ans2 {            println!("出错了!{}", i);            println!("str = {}", str);            println!("arr = {:?}", arr);            println!("m = {}", m);            println!("ans1 = {}", ans1);            println!("ans2 = {}", ans2);            break;        }    }    println!("测试结束");}
// 暴力方法// 为了测试fn max_len1(str1: &str, arr: &mut Vec<i32>, m: i32) -> i32 {    let s = str1.as_bytes();    let n = s.len() as i32;    let mut ans = 0;    for c in 'a' as u8..='z' as u8 {        for i in 0..n {            let mut j = n - 1;            while j >= i {                if ok(s, i, j, c, arr, m) {                    ans = get_max(ans, j - i + 1);                    break;                }                j -= 1;            }        }    }    return ans;}
// 为了测试fn ok(s: &[u8], l: i32, r: i32, c: u8, arr: &mut Vec<i32>, mut m: i32) -> bool {    for i in l..=r {        if s[i as usize] == c {            continue;        }        if arr[i as usize] == 0 || m == 0 {            return false;        }        m -= 1;    }    return true;}
// 正式方法fn max_len2(str1: &str, arr: &mut Vec<i32>, m: i32) -> i32 {    let s = str1.as_bytes();    let n = s.len() as i32;    let mut ans = 0;    for aim in 'a' as u8..='z' as u8 {        // 右边界        // [l..r)        let mut r = 0;        // 用了几次修改了        // change == m 用完的时候        let mut change = 0;        for l in 0..n {            // l......r ->            while r < n {                if s[r as usize] == aim {                    r += 1;                    continue;                }                // s[r] != aim                if arr[r as usize] == 0 || change == m {                    break;                }                // s[r] != aim && arr[r] == 1 && change < m                change += 1;                r += 1;            }            // l....r-1 r            // X l+1            ans = get_max(ans, r - l);            if s[l as usize] != aim && arr[l as usize] == 1 {                change -= 1;            }            // r r            // l l            // X            r = get_max(r, l + 1);        }    }    return ans;}
fn get_max<T: Clone + Copy + std::cmp::PartialOrd>(a: T, b: T) -> T {    if a > b {        a    } else {        b    }}
// 为了测试fn random_string(n: i32, r: i32) -> String {    let mut arr = String::new();    for _i in 0..n {        arr.push((rand::thread_rng().gen_range(0, r) as u8 + 'a' as u8) as char);    }    return arr;}
// 为了测试fn random_array(n: i32) -> Vec<i32> {    let mut arr: Vec<i32> = vec![];    for _i in 0..n {        arr.push(rand::thread_rng().gen_range(0, 2));    }    return arr;}

// SPDX-License-Identifier: MITpragma solidity ^0.8.17;
contract Hello{    function main() public pure returns (int32){    bytes memory s = "bbbcdbcade";    int32[] memory arr = new int32[](10);    arr[0] = 1;    arr[1] = 1;    arr[2] = 0;    arr[3] = 1;    arr[4] = 0;    arr[5] = 1;    arr[6] = 0;    arr[7] = 0;    arr[8] = 1;    arr[9] = 0;    int32 m = 4;    return maxLen2(s,arr,m);    }
  // 正式方法  function maxLen2(bytes memory s, int32[] memory arr, int32 m) public pure returns (int32){    int32 n = int32(int(s.length));    int32 ans = 0;    for (bytes1 aim = 'a'; aim <='z'; aim = bytes1(uint8(aim)+1)) {      // 右边界      // [l..r)      int32 r = 0;      // 用了几次修改了      // change == m 用完的时候      int32 change = 0;      for (int32 l = 0; l < n; l++) {        // l......r ->        while (r < n) {          if (s[uint32(r)] == aim) {            r++;            continue;          }          // s[r] != aim          if (arr[uint32(r)] == 0 || change == m) {            break;          }          // s[r] != aim && arr[r] == 1 && change < m          change++;          r++;        }        // l....r-1 r        // X l+1        ans = getMax(ans, r - l);        if (s[uint32(l)] != aim && arr[uint32(l)] == 1) {          change--;        }        // r r        // l l        // X        r = getMax(r, l + 1);      }    }    return ans;  }
    function getMax(int32 a,int32 b) public pure returns (int32){        if(a>b){            return a;        }else{            return b;        }    }
}