AtCoder Beginner Contest 136(C - Build Stairs)

1. #include< bits/stdc++.h >
2. using namespace std;
3. int main()
4. {
5. int n, m;
6. int vc[100001];
7. cin >> n;
8. for(int i = 0; i < n; i++){
9. cin >> vc[i];
10. }
11. for(int i = n - 1; i > 0; i--) {
12. if(vc[i] < vc[i-1]) vc[i - 1] -= 1;
13. }
14. for(int i = 1; i < n; i++) {
15. if(vc[i-1] > vc[i]) return cout << "No" << endl, 0;
16. }
17. cout << "Yes" << endl;
18. return 0;
19. }