Answer:
// here is code in C.
#include <stdio.h>
void main()
{
//declare variables
int N,a,b,c;
printf("Enter a value for N: " );
// read the value from user
scanf("%d",&N);
// validate the input
while(N<=0)
{
// if the input is not positive
printf("wrong input!!");
printf("\\Please enter a positive number: ");
scanf("%d",&N);
}
printf("\\All the combinations of 3 numbers that give sum equal to %d:",N);
// find all the combinations that sum equal to N
for( a=1;a< N-1;a++)
{
for(b= 1;b< N-1; b++)
{
for(c=1; c< N-1;c++)
{
if(a+b+c==N)
{
// print the output
printf("\\%d+%d+%d=%d",a,b,c,N);
}
}
}
}
}
Step-by-step explanation:
Declare variables a,b,c to find the all combinations and N to store the input number from user.Read the input from user. If user enter a negative number Then it will again ask user to enter a positive number.Then it will find all combinations of three numbers that will give sum equal to N with the help of three for loops.
Output:
Enter a value for N: -4
wrong input!!
Please enter a positive number: 6
All the combinations of 3 numbers that give sum equal to 6:
1+1+4=6
1+2+3=6
1+3+2=6
1+4+1=6
2+1+3=6
2+2+2=6
2+3+1=6
3+1+2=6
3+2+1=6
4+1+1=6