Question

Exercise #1: Develop a program that prints out the sum of each column of a two-dimensional array The program defines method sumColumn takes a two-dimensional array of integers and returns a single dimensional array that stores the sum of columns of the passed array. The program main method prompts the user to enter a 3-by-4 array, prints out the array, and then calls method sumColumaso). Finally, it prints out the array retuned by method sumColumoso. Document your code, and organize and space the outputs properly as shown below. C++ students instead of asking the user for input, you must read it from a file See appendix for more information. Sample run 1: Enter a value: 9 Enter a value: 1 Enter a value: 2 Enter a value: 4 Enter a value: 3 0 The entered matrix: WN W ON 09) WO

I need this code in C++. Should be able to read from a file as stated in the directions

Answer 1

i have written code in c++ in codeblocks,its working fine in my ide.ihave attached the output also.if you have any doubt feel free to ask.

CODE 1:taking input from input,txt file.

first make a input,txt file where you are saving your source code.

code:

#include <iostream>

using namespace std;
int* sumColumns(int[3][4]);//prototype of sumColumns() function
int main()
{
FILE *in;
int i=9,j=0;
int a[3][4];
in = fopen("input.txt", "r");//opening input.txt to take input
   if (in == NULL) {
       printf("Cannot open source file.\n");
       exit(1);
   }
   for(i=0;i<3;i++)
{
for(j=0;j<4;j++)
fscanf(in,"%d ",&a[i][j]);//storing values from input.txt int array

}
cout<<"The entered matrix:"<<endl;
for(i=0;i<3;i++)
{
for(j=0;j<4;j++)
cout<<a[i][j]<<" ";//printing array
cout<<endl;
}
int *sumcolumn=sumColumns(a); //returned array
for(j=0;j<4;j++)
{
cout<<"Sum of column"<<" "<<j<<" "<<sumcolumn[j]<<endl;//printing sum of column
}

fclose(in);

return 0;
}

int* sumColumns(int a[3][4])
{
int i=0,j=0;
int * sumcolumn=new int[4];
for(j=0;j<4;j++)
{
sumcolumn[j]=0;
}

for(j=0;j<4;j++)
{
for(i=0;i<3;i++)
sumcolumn[j]+=a[i][j];

}

return sumcolumn;

}

input:

Help input - Notepad File Edit Format View 9 1 24 2 280 3 3 3 3

output:

The entered matrix: 9 1 24 2 280 3 3 3 3 Sum of column 14 Sum of column 1 6 Sum of column 2 13 Sum of column 3 7 execution time: 0.031 s Process returned o (Oxo) Press any key to continue.

CODE2: taking input from user

code:

#include <iostream>

using namespace std;
int* sumColumns(int[3][4]);
int main()
{

int i=0,j=0;
int a[3][4];

for(i=0;i<3;i++)
{
for(j=0;j<4;j++)
{cout<<"Enter a value:";//taking input
cin>>a[i][j];}
}

cout<<"The entered matrix:"<<endl;
for(i=0;i<3;i++)
{
for(j=0;j<4;j++)
cout<<a[i][j]<<" ";//printing array
cout<<endl;
}
int *sumcolumn=sumColumns(a); //returned array
for(j=0;j<4;j++)
{
cout<<"Sum of column"<<" "<<j<<" "<<sumcolumn[j]<<endl;//printing sum of column
}

return 0;
}

int* sumColumns(int a[3][4])
{
int i=0,j=0;
int * sumcolumn=new int[4];
for(j=0;j<4;j++)
{
sumcolumn[j]=0;
}

for(j=0;j<4;j++)
{
for(i=0;i<3;i++)
sumcolumn[j]+=a[i][j];

}

return sumcolumn;

}

input/output:

Enter a value:9 Enter a value:1 Enter a value: 2 Enter a value:4 Enter a value: 2 Enter a value: 2 Enter a value: 8 Enter a value: 0 Enter a value:3 Enter a value:3 Enter a value:3 Enter a value:3 The entered matrix: 9 1 24 2 280 3 3 3 3 Sum of column 14 Sum of column 1 6 Sum of column 2 13 Sum of column 3 7 Process returned @ (exe) Press any key to continue. execution time : 35.937 s