97. 交错字符串
给定三个字符串 s1, s2, s3, 验证 s3 是否是由 s1 和 s2 交错组成的。
示例 1:
输入: s1 = “aabcc”, s2 = “dbbca”, s3 = “aadbbcbcac”
输出: true
示例 2:
输入: s1 = “aabcc”, s2 = “dbbca”, s3 = “aadbbbaccc”
输出: false
class Solution {
public boolean isInterleave(String s1, String s2, String s3) {
if((s1.length() + s2.length()) != s3.length()) return false;
boolean[][] dp = new boolean[s2.length() + 1][s1.length() + 1];
dp[0][0] = true;
for(int i = 1; i <= s1.length(); i++){
dp[0][i] = dp[0][i-1]&&s1.charAt(i-1)==s3.charAt(i-1)? true : false;
}
for(int i = 1; i <= s2.length(); i++){
dp[i][0] = dp[i-1][0]&&s2.charAt(i-1)==s3.charAt(i-1)? true : false;
}
for(int i = 1; i < dp.length; i++){
for(int j = 1; j < dp[0].length; j++){
dp[i][j] = (dp[i][j-1] && s1.charAt(j-1) == s3.charAt(i + j-1)) || (dp[i - 1][j] && s2.charAt(i-1) == s3.charAt(i + j-1));
}
}
return dp[s2.length()][s1.length()];
}
}