Download int sumDigit

CSC 2100: Introduction to Problem Solving and Computer Programming
Fall 2011, Test 1, September 23, 2011
Time: 55 minutes 100 Points
Name ______________________
1. [10 Points] Convert the following while loop to a for loop
int x = 5;
while ( x < 50 )
{
cout << x;
x++;
}
for (x = 5; x < 50; x++)
cout << x;
2. [10 Points] Convert a following for loop to a while loop
for (x = 50; x > 5; x--)
cout << x;
x = 5;
while ( x > 50)
{
cout << x;
x--;
}
3. [10 Points]What would be the output of the following code segment?
int balance = 29;
while ( 5 )
{
if (balance < 9)
Break;
balance = balance – 9;
}
cout << balance;
2
4. [10 Points] Given the following function definition
void calc (int a, int& b)
{
int c;
c = a + 2;
a = a * 3;
b = c + a;
}
What is the output of the following code fragment that invokes calc?
(All variables are of type int)
x = 1;
y = 2;
z = 3;
calc(x, y);
cout << x << "
" << y << "
"
<< z << endl;
1 6 3
5. [10 Points] Write program to display miles to kilometer conversion table (1 miles =
1.609 kilometer) as shown below for up to 200 miles. You must use for loop for this
program.
Miles Kilometer
1
1.609
2
3.218
...
……..
#include <iostream>
using namespace std;
int main()
{
int mile;
cout << setw(10) << “Mile” << setw(10) << “Kilometer”;
cout << fixed << setprecision(3);
for (mile = 1; mile <201; < mile ++)
cout << setw(10) << Mile << setw(10) << mile*1.609;
}
6. [10 Points] Write a program that will read an unspecified numbers of integers from
keyboard, determine how many even and how many odd numbers have been read. The
program should also compute the average of the integers read. The program should
display the number of odd integers, the number of even integers; and the average. Your
program should stop when user enters 0.
#include <iostream>
using namespace std;
int main()
{
int num, even=0, odd=0;
double total=0, avg=0;
while(true)
{
cout << “Enter an integer, 0 to quit:”;
cin >> num;
if(num == 0)
break;
else if(num % 2 == 0)
even++;
else
odd++;
total = total + num;
}
if((even+odd) != 0)
avg = total / (even + odd);
cout << “Even: “ << even << “ odd: “ << odd << “ Average: “ <<
avg << endl;
}
7. [10 Points] Write a function which will receive an integer as input and will print a
inverse triangle pattern. The input indicates how many lines will there be in the inverse
triangle. For example if 7 is passed to the function it will print the following pattern.
1234567
123456
12345
1234
123
12
1
void inverseTriangle (int x)
{
int i; j;
for( i = 0; i < x; i++)
{
for( j = 1; j <= (x - i); j++)
cout << j << “ “;
cout << endl;
}
8. [10 Points] Write a function that computes the sum of the digits of an integer. The
prototype of the function is int sumDigit(int). For example, sumDigit(521) returns
5+2+1 = 8.
Hint: use % operator to extract digits and the / operator to remove the extracted digit.
Use a loop to repeatedly extract and remove the digits until all the digits are extracted.
int sumDigit (int x)
{
int answer = 0;
while (x !=0)
{
answer = answer + x % 10;
x = x/10;
}
return answer;
}
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