# Program to find maximum number of coins we can collect in Python

PythonServer Side ProgrammingProgramming

Suppose we have a 2D matrix where each cell stores some coins. If we start from [0,0], and can only move right or down, we have to find the maximum number of coins we can collect by the bottom right corner.

So, if the input is like

 1 4 2 2 0 0 0 5

then the output will be 14, as we take the path: [1, 4, 2, 2, 5]

To solve this, we will follow these steps−

• for r in range 1 to row count of A, do

• A[r, 0] := A[r, 0] + A[r-1, 0]

• for c in range 1 to column count of A, do

• A[0, c] := A[0, c] + A[0, c-1]

• for r in range 1 to size of A, do

• for c in range 1 to size of A[0], do

• A[r, c] = A[r, c] + maximum of (A[r-1, c] and A[r, c-1]

• return value of bottom right corner of A

Let us see the following implementation to get better understanding−

## Example

Live Demo

class Solution:
def solve(self, A):
for r in range(1, len(A)):
A[r][0] += A[r-1][0]
for c in range(1, len(A[0])):
A[0][c] += A[0][c-1]
for r in range(1, len(A)):
for c in range(1, len(A[0])):
A[r][c] += max(A[r-1][c], A[r][c-1])
return A[-1][-1]
ob = Solution()
matrix = [ [1, 4, 2, 2], [6, 0, 0, 5] ]
print(ob.solve(matrix))

## Input

matrix = [
[1, 4, 2, 2],
[6, 0, 0, 5]
]

## Output

14
Published on 05-Oct-2020 13:44:06