Why is this isn't working? Please help

#1

Why is this isn’t working?
Please help.


Please tell any other optimized approach that you can think of.

#2

Hey @cbcao263
What you are doing is finding min in ith row and then traversing that row to check if its maximum as well

Instead do this
Find min,its index in every row then check its column if its maximum or not

#3

Am I not checking in the Column as For every i I am changing j
Therefore mat[i][j] is changing the columns.

#4

No changing j means u are traversing the row not the column

#5

Sir, Like it is a vector in vector.
Think it as a 2D Matrix
Let’s in first case when i=0
I took j=0 till mcol

means it will traverse m[0][0] then m[0][1] and till m[0][mcol-1]
Here You can check 0 is fixed which is the row number and j(column) is changing.

Am I wrong or right
?

#6

Yeah u are absolutely correct but
m[0][0] m[0][1] m[0][2] is 0 th row all elements
And u have to check the columns
so it should be say u get min of ith row at k
then m[0][k] m[1][k]… u have to check this

when u print a 2d matrix u do

for(int i=0;i<n;i++){
for(int j=0;j<m;j++){
}
}

This print row wise correct

#7

Is it correct now

#8

Nope
Do one thing

  1. Caculate min,min_index for each row and store it in vector of pairs
    2)Traverse the array say min is m and index is i,k (ith row ,kth column)
    then check for(int j=0;j<n;j++) if arr[i][k] is maximum in all arr[j][k] then store it in ans
#9

Hey @cbcao263
Here I solved it in 2 ways


I optimized memory in 2nd soln

#10

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