最长公共子序列

class Solution {
    public int longestCommonSubsequence(String text1, String text2) {
        // 重点是二维表格写出来，
        // 推出来dp公式dp[i][j] = Math.max(dp[i][j-1], dp[i-1][j])   或者相等情况下 dp[i][j] = dp[i-1][j-1] + 1;

        int[][] dp = new int[text1.length()+1][text2.length()+1];
        for(int i = 1; i <= text1.length(); i++ ) {
            for(int j = 1; j <= text2.length(); j++) {
                if(text1.charAt(i-1) == text2.charAt(j-1)) {
                    dp[i][j] = dp[i-1][j-1] + 1;
                }
                else {
                    dp[i][j] = Math.max(dp[i][j-1], dp[i-1][j]);
                }
            }
        }
        return dp[text1.length()][text2.length()];



    }
}