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

解法一：

class Solution {
public:
    int findMaxConsecutiveOnes(vector<int>& nums) {
        if(nums.empty())
            return 0;
        int max_len = 0;
        int start = -1;
        int cur_max = 0;
        for(int i=0; i<nums.size(); ++i){
            if(nums[i] == 1 && start == -1) {
                start = i;
                cur_max = 1;
            }
            else if(nums[i] == 1) { 
                cur_max = std::max(cur_max, i-start+1);
            }
            else {
                start = -1;
                continue;
            }
            max_len = std::max(cur_max, max_len);
        }

        return max_len;
    }
};

解法二：

class Solution {
public:
    int findMaxConsecutiveOnes(vector<int>& nums) {
        int max = 0;
        int sum = 0;
        for(int i=0; i<nums.size(); ++i){
            sum = (sum + nums[i]) * nums[i];
            if(sum > max) max = sum;
        }
        return max;
    }
};