Digits Sum (Codeforces 1553A)
Tags: Math, number theory

Let's define $$$S(x)$$$ to be the sum of digits of number $$$x$$$ written in decimal system. For example, $$$S(5) = 5$$$, $$$S(10) = 1$$$, $$$S(322) = 7$$$.We will call an integer $$$x$$$ interesting if $$$S(x + 1) < S(x)$$$. In each test you will be given one integer $$$n$$$. Your task is to calculate the number of integers $$$x$$$ such that $$$1 \le x \le n$$$ and $$$x$$$ is interesting.

Input: The first line contains one integer $$$t$$$ ($$$1 \le t \le 1000$$$)  — number of test cases.Then $$$t$$$ lines follow, the $$$i$$$-th line contains one integer $$$n$$$ ($$$1 \le n \le 10^9$$$) for the $$$i$$$-th test case.

Output: Print $$$t$$$ integers, the $$$i$$$-th should be the answer for the $$$i$$$-th test case.

Note: The first interesting number is equal to $$$9$$$.

Sample Inputs:
5
1
9
10
34
880055535

Sample Outputs:
0
1
1
3
88005553

Solution (Python):
for s in [*open(0)][1:]:
    print((int(s) + 1) // 10)

Solution (Python):
for _ in range(int(input())):
    n = int(input())
    if n < 9:
        print(0)
    elif str(n)[-1] != '9':
        print(n // 10)
    else:
        print(n // 10 + 1)

Solution (Python):
t = int(input())
for _ in range(t):
    n = int(input())
    print((n + 1) // 10)