TASK_052 - AquaBlitz11's Solution

#include <bits/stdc++.h>

using namespace std;

int main()
{
    int n;
    scanf("%d", &n);

    bool down = false, fail = false;
    int v = 0;
    for (int i = 0; i < n && !fail; ++i) {
        int x;
        scanf("%d", &x);
        if (x == v) {
            fail = true;
        } else if (x > v) {
            if (down)
                fail = true;
        } else { // x < v
            down = true;
        }
        v = x;
    }
    if (fail)
        printf("No\n");
    else
        printf("Yes\n");

    return 0;
}