river sizes prompt

gistfile1.txt

// RIVER SIZES

// You are given a two-dimensiona array (matrix) of potentially unequal height and width containing only 0s and 1s. 
// Each 0 represents land, and each 1 represents part of a river. A river consists of any number of adjacent 1s forming 
// a river determine its size. Write a function that returns an array of the sizes of all rivers represented in the input 
// matrix. Note that these sizes do not need to be in any particular order.

Sample input:
[
[1,0,0,1,0],
[1,0,1,0,0],
[0,0,1,0,1],
[1,0,1,0,1],
[1,0,1,1,0]
]

Sample output:
[1,2,2,2,5]
(1 length of 2 river,
3 length of 2 rivers,
1 length of 5 river)

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