trail 더블릿

#include <stdio.h>
#include <stack>
 
using namespace std;
 
int arr[1005] = { 0 };
 
int main() {
    int n;
    scanf("%d", &n);
 
    while (1) {
        stack<int> stk;        
        
        for (int i = 0; i < n; i++) {
            scanf("%d", &arr[i]);
            if (arr[i] == 0)
                return 0;
        }
        
        int idx = 0;
        for (int i = 1; i <= n; i++) {
            stk.push(i);
            while (stk.top() == arr[idx]) {                
                stk.pop();
                idx++;
                if (stk.empty() == true)
                    break;                                
            }
        }
        if (stk.empty() == true)
            printf("Yes\n");
        else
            printf("No\n");
    }
}