LeetCode Interleaving String

LeetCode Interleaving String

 

Given s1, s2, s3, find whether s3 is formed by the interleaving of s1 and s2.

For example,
Given:
S1 ="aabcc",
S2 ="dbbca",

When s3 ="aadbbcbcac", Return true.
When s3 ="aadbbbaccc", Return false.

Question: Can the s1 and s2 strings be combined into S3.

Idea: DP is done. dp [I + 1] [j + 1] indicates s1 [0... i] and s2 [0... j] whether it can be combined into s3 [I + j + 1]. When dp [I] [j + 1] is true, if s1 [I + 1] = s3 [I + j + 1], dp [I + 1] [j + 1] will meet the requirements, the same is true for dp [I + 1] [j.

 

 

public class Solution {    public boolean isInterleave(String s1, String s2, String s3) {        int m = s1.length(), n = s2.length();    if (m + n != s3.length()) return false;        boolean dp[][] = new boolean[m+1][n+1];    dp[0][0] = true;    for (int i = 0; i < n; i++)     dp[0][i+1] = dp[0][i] && (s2.charAt(i) == s3.charAt(i));    for (int i = 0; i < m; i++)    dp[i+1][0] = dp[i][0] && (s1.charAt(i) == s3.charAt(i));        for (int i = 0; i < m; i++)    for (int j = 0; j < n; j++)    dp[i+1][j+1] = (dp[i][j+1] && (s1.charAt(i) == s3.charAt(i+j+1)) ||    (dp[i+1][j] && (s2.charAt(j) == s3.charAt(i+j+1))));        return dp[m][n];    }}