WAP返回两个字符串之间最长的公共子字符串的长度

Question

Two strings are given and we have to find the length of longest common substring. I don't know what's wrong with my code.

The outer loop takes a substring of B and the inner loop increases the substring by one character at a time.

For the input "www.lintcode.com code", "www.ninechapter.com code" the output is coming 5 but it should be 9

    public class Solution {
/**
 * @param A, B: Two string.
 * @return: the length of the longest common substring.
 */
public int longestCommonSubstring(String A, String B) {
    // write your code here
    int k = 0, temp = 0;
    if(B.length() == 0){
        return 0;
    }

    for(int i = 0; i < B.length()-1; i++){
        String bb = B.substring(i, i+1);
        if(A.contains(bb)){

            for(int j = 1; j < A.length()-i; j++){
                String bbb = B.substring(i, i+j);
                if(!A.contains(bbb))
                    break;
                temp = bbb.length();
            }
        }
        if(temp > k)
            k = temp;
    }

    return k;
}

}

Answer 1

Just replace this:

for(int j = 1; j < A.length()-i; j++)

with this:

for(int j = 1; j < B.length()-i+1; j++)

Answer 2

I believe you could reduce your function size a little with this...not sure if your method is more efficient or not though...

public int longestCommonSubstring(String A, String B) {
    int longestSubstring = 0;
    for (int x=0; x < A.length(); x++) {
        for (int y=x; y < A.length() + 1; y++) {
            String testString = A.substring(x,y);
            if (B.contains(testString) && (testString.length() > longestSubstring)) {
                longestSubstring = testString.length();
            }
        }
    }
    return longestSubstring;
}