【大战蓝桥杯】 算法·每日一题（详解+多解）-- day10

提示：

1 <= nums.length <= 105
nums[i] 不是 0 就是 1

public int findMaxLength(int[] nums) {
    int res=0;
    int n=nums.length;
    int slow=0, fast=0;
    int zeroNum=0, oneNum=0;
    
    while (fast<n){
        for (int i=0; i<2 && fast<n; i++){
            if (nums[fast++]==0) zeroNum++;
            else oneNum++;
        }
        if (oneNum==zeroNum) res = Math.max(res, fast-slow);
        else {
            if (nums[slow++]==0) zeroNum--;
            else oneNum--;
        }
    }

    return res;
}

class Solution {
    public int findMaxLength(int[] nums) {
        Map<Integer, Integer> map = new HashMap<>();
        map.put(0, -1);
        int sum = 0, res = 0;
        for (int i = 0; i < nums.length; ++i) {
            sum += nums[i] == 1 ? 1 : -1;
            if (map.containsKey(sum)) {
                res = Math.max(res, i - map.get(sum));
            } else {
                map.put(sum, i);
            }
        }
        return res;
    }
}