Pretty nice hints, only thing I got wrong were states for DP. Can you tell me reason to take [i][j] there and why not [k] where k indicates if the element was added to increasing or decreasing sequence or none

I am here trying to solve problem in O(n) space,

I don't know why my code gives me few WAs, well do we nee dto keep track of diagonal values? As my code doesn't deos that. If yes, why?

#include<iostream>

using namespace std;

int max(int a,int b){

if(a>b) return a;

return b;

}

int main(){

int size;