max_substring_with_k_chars.go

package main
import "fmt"

func max(a,b int) int {
    if a > b {
        return a
    } else {
        return b
    }
}

func lengthOfLongestSubstringKDistinct(s string, k int) int {
    sMap := make(map[byte]int,len(s))

    start,end,targetCount,maxLen := 0,0,0,math.MinInt32
    
    for end<len(s) {
         
        if sMap[s[end]] == 0 {
            targetCount+=1
        }
        
        sMap[s[end]]+=1
        
        for targetCount > k && start<len(s) {

            sMap[s[start]]-=1
            
            if sMap[s[start]] == 0 {
                targetCount -= 1
            }
            start+=1
            
        }
        
        maxLen = max(maxLen,end-start+1)
        
        end+=1
    }
    
    if maxLen == math.MinInt32 {
        return 0
    } else {
        return maxLen
    }
}


func main() {




}