[LeetCode] 485. Max Consecutive Ones

Given a binary array, find the maximum number of consecutive 1s in this array.

Example 1:

Input: [1,1,0,1,1,1]
Output: 3
Explanation: The first two digits or the last three digits are consecutive 1s.
    The maximum number of consecutive 1s is 3.

Note:

• The input array will only contain 0 and 1.
• The length of input array is a positive integer and will not exceed 10,000

最大连续1的个数。

给定一个二进制数组， 计算其中最大连续1的个数。

思路是追击型的two pointer，但是我们在实现的时候可以不需要用到指针，详细参见代码。这道题其实也是隐式的滑动窗口类型的题。

时间O(n)

空间O(1)

Java实现

class Solution {
    public int findMaxConsecutiveOnes(int[] nums) {
        // corner case
        if (nums.length == 0 || nums == null) {
            return 0;
        }

        // normal case
        int max = 0;
        int count = 0;
        for (int i = 0; i < nums.length; i++) {
            if (nums[i] == 1) {
                count++;
                max = Math.max(max, count);
            } else {
                count = 0;
            }
        }
        return max;
    }
}

JavaScript实现

/**
 * @param {number[]} nums
 * @return {number}
 */
var findMaxConsecutiveOnes = function (nums) {
    let max = 0;
    let count = 0;
    for (let i = 0; i < nums.length; i++) {
        if (nums[i] == 1) {
            count++;
            max = Math.max(max, count);
        } else {
            count = 0;
        }
    }
    return max;
};

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