# Python: Find the indices for which the numbers in the list drops

## Python Programming Puzzles: Exercise-23 with Solution

Write a Python program to find the indices at which the numbers in the list drop.

NOTE: You can detect multiple drops just by checking if nums[i] < nums[i-1].

Input: [0, -1, 3, 8, 5, 9, 8, 14, 2, 4, 3, -10, 10, 17, 41, 22, -4, -4, -15, 0] Output: [1, 4, 6, 8, 10, 11, 15, 16, 18] Input: [6, 5, 4, 3, 2, 1] Output: [1, 2, 3, 4, 5] Input: [1, 19, 5, 15, 5, 25, 5] Output: [2, 4, 6]

**Sample Solution-1:**

**Python Code:**

```
#License: https://bit.ly/3oLErEI
def test(nums):
drop_indices = []
for i in range(1, len(nums)):
if nums[i] < nums[i - 1]:
drop_indices.append(i)
return drop_indices
nums = [0, -1, 3, 8, 5, 9, 8, 14, 2, 4, 3, -10, 10, 17, 41, 22, -4, -4, -15, 0]
print("Original list:")
print(nums)
print("Indices for which the numbers of the said list drops.:")
print(test(nums))
nums = [6,5,4,3,2,1]
print("\nOriginal list:")
print(nums)
print("Indices for which the numbers of the said list drops.:")
print(test(nums))
nums = [1,19,5,15,5,25,5]
print("\nOriginal list:")
print(nums)
print("Indices for which the numbers of the said list drops.:")
print(test(nums))
```

Sample Output:

Original list: [0, -1, 3, 8, 5, 9, 8, 14, 2, 4, 3, -10, 10, 17, 41, 22, -4, -4, -15, 0] Indices for which the numbers of the said list drops.: [1, 4, 6, 8, 10, 11, 15, 16, 18] Original list: [6, 5, 4, 3, 2, 1] Indices for which the numbers of the said list drops.: [1, 2, 3, 4, 5] Original list: [1, 19, 5, 15, 5, 25, 5] Indices for which the numbers of the said list drops.: [2, 4, 6]

**Flowchart:**

**Sample Solution-2:**

**Python Code:**

```
#License: https://bit.ly/3oLErEI
def test(nums):
return [i for i in range(1, len(nums)) if nums[i] < nums[i - 1]]
nums = [0, -1, 3, 8, 5, 9, 8, 14, 2, 4, 3, -10, 10, 17, 41, 22, -4, -4, -15, 0]
print("Original list:")
print(nums)
print("Indices for which the numbers of the said list drops.:")
print(test(nums))
nums = [6,5,4,3,2,1]
print("\nOriginal list:")
print(nums)
print("Indices for which the numbers of the said list drops.:")
print(test(nums))
nums = [1,19,5,15,5,25,5]
print("\nOriginal list:")
print(nums)
print("Indices for which the numbers of the said list drops.:")
print(test(nums))
```

Sample Output:

Original list: [0, -1, 3, 8, 5, 9, 8, 14, 2, 4, 3, -10, 10, 17, 41, 22, -4, -4, -15, 0] Indices for which the numbers of the said list drops.: [1, 4, 6, 8, 10, 11, 15, 16, 18] Original list: [6, 5, 4, 3, 2, 1] Indices for which the numbers of the said list drops.: [1, 2, 3, 4, 5] Original list: [1, 19, 5, 15, 5, 25, 5] Indices for which the numbers of the said list drops.: [2, 4, 6]

**Flowchart:**

**Python Code Editor :**

**Have another way to solve this solution? Contribute your code (and comments) through Disqus.**

**Previous:** Compute the sum of the ASCII values of the upper-case characters in a given string.

**Next:** Create a list whose ith element is the maximum of the first i elements of the input list.

**What is the difficulty level of this exercise?**

Test your Programming skills with w3resource's quiz.

**Weekly Trends**- Python Interview Questions and Answers: Comprehensive Guide
- Scala Exercises, Practice, Solution
- Kotlin Exercises practice with solution
- MongoDB Exercises, Practice, Solution
- SQL Exercises, Practice, Solution - JOINS
- Java Basic Programming Exercises
- SQL Subqueries
- Adventureworks Database Exercises
- C# Sharp Basic Exercises
- SQL COUNT() with distinct
- JavaScript String Exercises
- JavaScript HTML Form Validation
- Java Collection Exercises
- SQL COUNT() function
- SQL Inner Join