The correct, optimal and working solution for programming question maximum-element on hackerrank

/* * Author: Arpit Bhayani * https://arpitbhayani.me */ #include <cmath> #include <cstdio> #include <cstdlib> #include <climits> #include <deque> #include <iostream> #include <list> #include <limits> #include <map> #include <queue> #include <set> #include <stack> #include <vector> #define ll long long #define MIN(a, b) a < b ? a : b #define MAX(a, b) a > b ? a : b using namespace std; int readline(char *str) { int i = 0; char ch; while((ch = getchar()) != '\n') { str[i++] = ch; } str[i] = '\0'; return i; } stack<ll int> s, m; int main(int argc, char *argv[]) { int t, x; ll int v, mx = -1; scanf("%d", &t); while(t--) { scanf("%d", &x); if(x == 1) { scanf("%lld", &v); if(mx == -1 || m.empty()) { mx = v; } else { mx = MAX(m.top(), v); } s.push(v); m.push(mx); } else if(x == 2) { s.pop(); m.pop(); } else { printf("%lld\n", m.top()); } } return 0; }