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CS 141Computer

Programming 1

Iteration Statements

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Question #1

Question

What are the syntax and/or logic errors in the following codes?

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Question #1

For(x=100,x>=1,x++) Cout<<x<<endl;

logic error is infinite loop . to correct it x-- so it counts 100 to 1

Answer

Question

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Question #1

The following code should output the odd integers from 19 to 1:

For( x=19;x>=1;x+=2)Cout<<x<<endl;

logic error infinite loop , to correct it x -= 2

Answer

Question

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Question #1

int x; while (x) { cout << x << endl;

x+=2;}

•x used without initialization , to correct it , int x =10•Infinite loop . to correct it , while(x<50)

Answer

Question

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Question #2Question

Find the output for each loop:

int x=1, t=0 , y;while(x<=3){

y = x*x;t=t+y;x++;

}cout << t << endl;

Answer

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Question #2Question

Find the output for each loop: Answer

int i, j=0;for (i=1; i<6; i++){

 if (i%2!=0){

cout << i*i , " << ;"

j+=i*i;} }cout << "\nj = " << j;

1, 9, 25j=35

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Question #2Question

Find the output for each loop:

Answer

for (int a = 1; a <= 1; a++) cout << a ;++

cout << a;

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Question #2Question

Find the output for each loop:

Answer

int counter = 12;do{

cout << "Good Luck \n;"counter;++

}while (counter < 12);

Good luck

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Question #2Question

Find the output for each loop:

Answer

int i = 5 ;do{cout << "***" << endl; i-- ;} while(i > 5);

***

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Question #3Question

Consider the following code segment:

int i;while (i < 10){cout << i << endl;i++;}

How could you initialize i so that the loop would be

traversed 10 times?

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Question #3Answer

int i=0;while (i < 10){cout << i << endl;i++;}

initialize i with 0

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Question #3Question

Consider the following code segment:

int i;while (i < 10){cout << i << endl;i++;}

If the body of the loop was kept as it is

above, how can you change the

initialization and the condition to print the

same output “the numbers 1 to 10”?

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Question #3Answer

int i;while (i < 10){cout << i << endl;i++;}

int i =1;while (i <= 10){cout << i << endl;i++;}

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Question #4Question

Write for statements that print the following sequences of values:

A) 20, 14, 8, 2, -4, -10B) 19, 27, 35, 43, 51

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Question #4Answer

A) 20, 14, 8, 2, -4, -10

B) 19, 27, 35, 43, 51

for(i =20 ; i>=-10; i-=6)cout << i << “,”;

for(i =19 ; i<=51; i+=8)cout << i << “,”;

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Question #5Question

Compute the number of times the statement in the body of the following

FOR loops will be executed.

int i , sum = 0;for (i=10;i>=1;i--)sum+=i;

int i , sum = 0;for (i=10;i>=1;i-=3)sum+=i;

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Question #5

Answer

int i , sum = 0;for (i=10;i>=1;i--)sum+=i;

int i , sum = 0;for (i=10;i>=1;i-=3)sum+=i;

10 Times

4 Times

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Problems

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Question #1Question

Write a program that asks the user to enter 5 integers and writes the

smallest value.

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Answer#include<iostream>

using namespace std;int main(){

int i,smallest,n;

for(i=0;i<5;++i){

cout<<"Enter an integer ";cin>>n;if(i==0) // first number

smallest = n;else if(n<smallest)

smallest = n;}//end for

cout<<"The smallest value is "<<smallest<<endl;return 0;

}

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Question #2Question

Write a program that reads a set integers, and then finds and prints the sum of the even and odd integers.  How many numbers in your set of integers? : 6

Start Entering: 2 4 3 6 7 1Sum of odd numbers = 11Sum of even numbers = 12

 

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Answer#include <iostream>using namespace std;int main(){

int numbers , x , sumOdd =0, sumEven=0;cout << "How many numbers in your set of integers? " ;cin >> numbers ;for (int i=0 ; i< numbers ; i++){

cin >> x;if (x%2==0)

sumEven+=x;else

sumOdd+=x;}cout << "Sum of odd numbers = " << sumOdd << endl;cout << "Sum of even numbers = " << sumEven << endl;return 0;

}

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Question #3Question

Write a program using for loop that generates the following output:

1 10 2 9 3 8 4 7 5 6 6 5 7 4 8 3 9 2 10 1

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Answer

#include <iostream>using namespace std;void main(){ int i, j;

for (i=1,j=10; i<=10 || j>=1 ; i++,j--) cout << i << " "<< j << " "; cout << endl;

system("pause");}

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Question #4Question

Write a program that reads two even integers then prints all even integers between them, following is a sample output

Enter min and max even numbers respectively:4 20The even numbers between 4 and 20:6 8 10 12 14 16 18 20

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#include <iostream>using namespace std;void main(){ int num1, num2, i; cout << "Enter min and max even numbers respectively : \n"; cin>>num1>>num2;

cout<< "The even numbers between "<<num1<<" and "<<num2<<" : \n";

for(i=num1;i<=num2;i++) if(i%2 ==0) cout<<i<<" ";

cout<<endl; system("pause");}

Answer

for(i=num1;i<=num2;i+=2) cout<<i<<" ";

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Evaluation

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Write a C++ program to calculate (a) to the power (b) .

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