min_insert_pali.go

package problem1312

/*
Given a string s. In one step you can insert any character at any index of the string.
Return the minimum number of steps to make s palindrome.
A Palindrome String is one that reads the same backward as well as forward.
*/

func minInsertions(s string) int {
	var n = len(s)
	var dp = make([][]int, n+1)
	for i := range dp {
		dp[i] = make([]int, n+1)
	}
	for i := 0; i < n; i++ {
		for j := 0; j < n; j++ {
			if s[i] == s[n-1-j] {
				dp[i+1][j+1] = dp[i][j] + 1
			} else {
				dp[i+1][j+1] = max(dp[i][j+1], dp[i+1][j])
			}
		}
	}
	return n - dp[n][n]
}

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