sliding window

[KevinACoder]

//209. Minimum Size Subarray Sum
func minSubArrayLen(sum int, nums []int) (ans int) {
    var start, end, tmpSum int
    ans = math.MaxInt32
    for start < len(nums) {
        //move 'end' to make slide window valid
        for end < len(nums) && tmpSum < sum {
            tmpSum += nums[end]
            end++
        }
        if tmpSum < sum {break} //not able to find a valid sliding window
        ans = Min(ans, end - start)
        //move slide window by increase 'start'
        tmpSum -= nums[start]
        start++
    }

    if ans == math.MaxInt32 {ans = 0}
    return
}

[KevinACoder]

//1004. Max Consecutive Ones III
func longestOnes(ones []int, k int) (ans int) {
    var start, end, zeros int
    for ; end < len(ones); end++ {
        if ones[end] == 0 {zeros++}
        //move 'start' util zeros are equal or less than k
        for zeros > k {
            //remove the head element, if it is zeros, reduce
            // num of zero in sliding window
            if ones[start] == 0 {zeros--}
            start++
        }
        ans = Max(ans, end - start + 1)
    }
    return
}