动态规划子序列问题系列一＞最长数对链

public int findLongestChain(int[][] pairs) {
        Arrays.sort(pairs, (a,b)->(a[0]-b[0]));
        int n = pairs.length;
        int[] dp = new int[n];
        for(int i = 0; i < n; i++) dp[i] = 1;

        int ret = 1;
        for(int i = 1; i < n; i++){
            for(int j = 0; j <= i-1; j++){
                if(pairs[j][1] < pairs[i][0])
                    dp[i] = Math.max(dp[j]+1,dp[i]);
            }
            ret = Math.max(ret,dp[i]);
        }

        return ret;
    }