The longest common non-declining subsequence (LIS) of dynamic programming

The longest common non-descending subsequence (LIS)

Problem Description

In a numeric sequence, find the longest sub-sequence (may not be continuous), so that this sub-sequence is not descending (non-decreasing).

Sample input

7

1 2 3 -1 -2 7 9

Sample output

5

Dynamic transfer equation: dp[i] = max{1, dp[j] + 1}

#include <bits/stdc++.h>
using namespace std;
int main(){
	int n;
	cin>>n;
	int s[n];
	for(int i = 0; i < n; i++){
		cin>>s[i];
	} 
	int dp[n];
	memset(dp, 0, sizeof(dp));
	int ans = -1;			//记录结果 
	for(int i = 0; i < n; i++){
		dp[i] = 1;
		for(int j = 0; j < i; j++){
			if(s[i] >= s[j] && dp[j] + 1 > dp[i]){
				dp[i] = dp[j] + 1;		//动态转移方程 
			}
 		}
 		ans = max(ans, dp[i]);
 	}
 	cout<<ans;
	return 0;
}