Matthew Lopez
ET2560 Intro to C
Unit 5 assignment 1
Pg. 238
1. Choose an appropriate kind of loop from Table 5.1 for solving each of the following problems.
a. Calculate the sum of the test scores of a class of 35 students. ( Hint: Initialize sum to zero before entering loop.) Endfile- controlled loop
b. Print weekly paychecks for a list of employees. The following data are to be entered interactively for each employee: ID, hours worked, and hourly pay rate. An ID of zero marks the end of the data. Sentinel- controlled loop
c. Process a data file of Celsius temperatures. Count how many are above 100° C. Input validation loop
Pg. 241 – 242
1. Predict the output of this program fragment: i = 0; while ( i <= 5)
{ printf("% 3d % 3d\ n", i, 10 - i); i = i + 1;
}
It will show the numbers that appear before 5 2. What is displayed by this program fragment for an input of 8? scanf("% d", & n); ev = 0; while ( ev < n)
{ printf("% 3d", ev); ev = ev + 2;
} printf("\ n") Show the numbers from 0 to 8 increasing by 2 each time
Pg. 246 – 247
1. What output values are displayed by the following while loop for a data value of 5? Of 6? Of 7? printf(" Enter an integer> "); scanf("% d", & x); product = x; count = 0; while ( count < 4)
{ printf("% d\ n", product); product *= x; count += 1; } No values are output
3. The following segment needs some revision. Insert braces where they are needed and correct the errors. The corrected code should take five integers and display their sum. count = 0; while ( count <= 5) count += 1; printf(" Next number> "); scanf("% d", & next_ num); next_ num += sum; printf("% d numbers were added; \ n", count); printf(" their sum is % d.\ n", sum);

Pg. 255 – 256
1. Write a loop that displays a table of angle measures along with their sine and cosine values. Assume that the initial and final angle measures ( in degrees) are available in init_ degree and final_ degree ( type int variables), and that the change in angle measure between table entries is given by step_ degree ( also a type int variable). Remember that the math library’s sin and cos functions take arguments that are in radians. #include <stdio.h> int main(){ double cosine, sine; double n; printf("Enter the value of n.\n"); scanf("%d",&n); for(count=1;count<=n;++count) //for loop terminates if count>n { sum+=count; /* this statement is equivalent to sum=sum+count */ } printf("Sum=%d",sum); return 0; }

6. What errors do you see in the following fragment? Correct the code so it displays all multiples of 4 from 0 through 100 .
For n = 0 ; n > 0 && n < 100; n = n + 4; printf("% d\ n", n);

Pg. 260
2. Correct the syntax and logic of the code that follows so that it prints all multiples of 4 from 0 through 100: for sum = 0; sum > 0 && sum < 100; sum = + 4; printf("% d\ n", sum);

Pg. 272
1. What is displayed by the following program segments, assuming m is 3 and n is 5?
a. for ( i = 1; i <= n; ++ i)
{ for ( j = 0; j < i; ++ j) { printf("*");
} printf("\ n");
}
b. for ( i = n; i > 0; -- i)
{ for ( j = m; j > 0; -- j) { printf("*");
} printf("\ n"); }

m is 3“*” n is 5 “*”
2. Show the output displayed by these nested loops: for ( i = 0; i < 3; ++ i) { printf(" Outer % 4d\ n", i); for ( j = 0; j < 2; ++ j) { printf(" Inner% 3d% 3d\ n", i, j);
} for ( k = 2; k > 0; -- k) { printf(" Inner% 3d% 3d\ n", i, k); } }

I is an outer 4 digit number that increases by 1
J is an inner two 3 digit number and only j increases by one
K is 2 but is greater than 0 and decreases by 1
Pg. 275
1. Which of the following code segments is a better way to implement a sentinel-controlled loop? Why?

The right side because the loop only continues as long as num doesn’t equal SENT.
Pg. 304
5. Rewrite the program segment that follows, using a for loop:
For (count = 0; i = 0); while ( i < n) { scanf("% d", & x); if ( x == i) ++ count; ++ i; }

6. Rewrite this for loop heading, omitting any invalid semicolons. for ( i = n; i < max; ++ i);