# PROBLEM LINK:

Practice

Contest: Division 1

Contest: Division 2

Contest: Division 3

Contest: Division 4

* Author:* jeevanjyot

*mexomerf, rivalq*

**Testers:***iceknight1093*

**Editorialist:**# DIFFICULTY:

TBD

# PREREQUISITES:

None

# PROBLEM:

An integer is said to be *lucky* if it contains the digit 7.

Given a positive integer X, is it lucky?

# EXPLANATION:

All that needs to be done is to check, for each digit of X, whether it equals 7.

Extracting all the digits of an integer can be done in a couple of different ways:

- The simplest way is to read X as a
*string*instead of an integer. Then, you can simply iterate over its characters and check whether each one equals`'7'`

or not. - Alternately, run the following algorithm:
- If X = 0, stop.
- Otherwise, let
`d = X%10`

.`d`

is the last digit of X, check whether it equals 7 or not. - Next, divide X by 10. This essentially removes the last digit of X.
- Run the above three steps in a loop; hence extracting every digit of X.

# TIME COMPLEXITY:

\mathcal{O}(1) per testcase.

# CODE:

## Code (Python) (String)

```
for _ in range(int(input())):
x = input()
print('Yes' if '7' in x else 'No')
```

## Code (Python) (Loop)

```
for _ in range(int(input())):
x = int(input())
ans = 'No'
while x > 0:
d = x%10
if d == 7: ans = 'Yes'
x //= 10
print(ans)
```