leetcode 97. Interleaving String
public class Solution {
public boolean isInterleave(String s1, String s2, String s3) {
if(s1.length()+s2.length()!=s3.length()) return false;
boolean[][] dp = new boolean[s1.length()+1][s2.length()+1];
dp[0][0] = true;
// j==0
for(int i= 1;i<=s1.length();i++){
if(s1.charAt(i-1)==s3.charAt(i-1)&&dp[i-1][0]){
dp[i][0] = true;
}
}
// i==0
for(int j=1;j<=s2.length();j++){
if(s2.charAt(j-1)==s3.charAt(j-1)&&dp[0][j-1]){
dp[0][j] = true;
}
}
// i>0 j>0
for(int i=1;i<=s1.length();i++){
for(int j=1;j<=s2.length();j++){
if((dp[i-1][j]&&s1.charAt(i-1)==s3.charAt(i+j-1))||
dp[i][j-1]&&s2.charAt(j-1)==s3.charAt(i+j-1)){
dp[i][j] = true;
}
}
}
return dp[s1.length()][s2.length()];
}
}