最小替换字串长度

问题描述

思路1

1. 统计每一种字符的个数。
2. 计算所有数字的总和与平均值。
3. 统计需要改变的长度
4. 统计超出平均值的字符, 将其替换为X
5. 找到字符串中k个X的最短字串长度

代码解析

public class Main {
    public static int solution(String input) {
        // Please write your code here
        int numA = 0, numS = 0, numD = 0, numF = 0;

        for (int i = 0; i < input.length(); i++) {
            char c = input.charAt(i);
            if (c == 'A')
                numA++;
            if (c == 'S')
                numS++;
            if (c == 'D')
                numD++;
            if (c == 'F')
                numF++;
        }
        int replace = 0;
        boolean replaceA = false, replaceS = false, replaceD = false, replaceF = false;
        
        if (numA > input.length() / 4) {
            replaceA = true;
            input=input.replace('A', 'X');
        }
        else
            replace += input.length() / 4 - numA;

        if (numS > input.length() / 4) {
            replaceS = true;
            input=input.replace('S', 'X');
        }
        else
            replace += input.length() / 4 - numS;

        if (numD > input.length() / 4) {
            replaceD = true;
            input=input.replace('D', 'X');
        }
        else
            replace += input.length() / 4 - numD;

        if (numF > input.length() / 4) {
            replaceF = true;
            input=input.replace('F', 'X');
        }
        else
            replace += input.length() / 4 - numF;


        int min = input.length();
        int tmp = 0;

        for (int i = 0; i < input.length(); i++) {
            if (input.charAt(i) != 'X')
                continue;
            int len = 0;
            for (int j = i; j < input.length(); j++) {
                if (input.charAt(j) == 'X') {
                    len++;
                }
                tmp++;
                if (len == replace)
                    break;
            }
            if (tmp < min)
                min = tmp;
            tmp=0;
        }

        return min;
    }

    public static void main(String[] args) {
        // You can add more test cases here
        System.out.println(solution("ADDF") == 1);
        System.out.println(solution("ASAFASAFADDD") == 3);
    }
}