I don't see any error on your code, everything is well written and simple. Except trying putting PUBLIC on your Class displayer. If you encounter the same problem again try to rebuild your whole code and try to recompile the whole code. Even try restarting your personal computer.
I would save memories in my opinion thats the most important thing.
Answer:
The program is written using PYTHON SCRIPT below;
N=int(input(" Enter number of Rows you want:"))
M=[] # this for storing the matrix
for i in range(N):
l=list(map(int,input("Enter the "+str(i+1)+" Row :").split()))
M.append(l)
print("The 2D Matrix is:\n")
for i in range(N):
print(end="\t")
print(M[i])
W=[] # to store the first non zero elemnt index
T=[] # to store that value is positive or negative
L=len(M[0])
for i in range(N):
for j in range(L):
if (M[i][j]==0):
continue
else:
W.append(j) # If the value is non zero append that postion to position list(W)
if(M[i][j]>0): #For checking it is positive or negative
T.append(+1)
else:
T.append(-1)
break
print()
print("The first Non Zero element List [W] : ",end="")
print(W)
print("Positive or Negative List [T] : ",end="")
print(T)
Explanation:
In order for the program to determine a set of test cases it takes in input of 2D matrix in an N numbet of rows.
It goes ahead to program and find the column index of the first non-zero value for each row in the matrix A, and also determines if that non-zero value is positive or negative. The If - Else conditions are met accordingly in running the program.