Link to this code:
https://cses.fi/paste/762897a333ad1078d7990a/""" 777 """
def solve():
n = int(input())
arr = list(map(int, input().split()))
index_map = [n] * (n + 1)
for index, value in enumerate(arr):
index_map[value] = index
rounds = 0
for cur_num in range(1, n + 1):
prev_num_index, cur_num_index = index_map[cur_num - 1], index_map[cur_num]
rounds += prev_num_index > cur_num_index
# print(prev_num_index, cur_num_index)
return rounds
T = 1
# T = int(input())
for _ in range(T):
res = solve()
print(res)
# print("YES" if res else "NO")
"""
- if the previous number occurs before the current number then both of them can be taken in a single round
- for this to happen for each num the index of previous num should be less than the index of current num,
formally -> prev_num_index < cur_num_index
then both of them belong to the same round
"""
