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counting sort

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	`1`	`+# COUNTING SORT`
	`2`	`+`
	`3`	`+- Counting sort is a sorting technique based on keys between a specific range.`
	`4`	`+- It works by counting the number of objects having distinct key values (kind of hashing).`
	`5`	`+- Then doing some arithmetic to calculate the position of each object in the output sequence.`
	`6`	`+`
	`7`	+```python
	`8`	`+def counting_sort(array, maxval):`
	`9`	`+ n = len(array)`
	`10`	`+ m = maxval + 1`
	`11`	`+ count = [0] * m # init with zeros`
	`12`	`+ for a in array:`
	`13`	`+ count[a] += 1 # count occurences`
	`14`	`+ i = 0`
	`15`	`+ for a in range(m): # emit`
	`16`	`+ for c in range(count[a]): # emit "count[a]" copies of "a"`
	`17`	`+ array[i] = a`
	`18`	`+ i += 1`
	`19`	`+ return array`
	`20`	`+`
	`21`	`+`
	`22`	`+arr = [1,4,7,2,1,3,2,1,4,2,3,2,1]`
	`23`	`+print("Output: ", counting_sort(arr, 7))`
	`24`	+```
	`25`	`+output:`
	`26`	+```
	`27`	`+[1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 4, 4, 7]`
	`28`	+```
	`29`	`+`
	`30`	`+<img src="https://cdn.programiz.com/sites/tutorial2program/files/Counting-sort-4_1.png" />`

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	`1`	`+def counting_sort(array, maxval):`
	`2`	`+ n = len(array)`
	`3`	`+ m = maxval + 1`
	`4`	`+ count = [0] * m # init with zeros`
	`5`	`+ for a in array:`
	`6`	`+ count[a] += 1 # count occurences`
	`7`	`+ i = 0`
	`8`	`+ for a in range(m): # emit`
	`9`	`+ for c in range(count[a]): # emit "count[a]" copies of "a"`
	`10`	`+ array[i] = a`
	`11`	`+ i += 1`
	`12`	`+ return array`
	`13`	`+`
	`14`	`+`
	`15`	`+arr = [1,4,7,2,1,3,2,1,4,2,3,2,1]`
	`16`	`+print("Output: ", counting_sort(arr, 7))`

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