Week_13

Week 13 Notes

Structures

Question 1 - Distance

Define a struct representing a point (x, y).

• Write a function distance which takes two points and finds Euclidean distance between these points. Use pow() and sqrt() functions from math library include <math.h>

In main function, take two points from user and print the between them.

Input	Output
3 0 0 4	5.00
11 7 3 21	16.12

Question 2 - Extreme Points

Write a program which takes an integer N and reads N points (given by their x and y coordinates) and determines the pair that is the farthest apart.

Use the point definition and distance function from the first question

Input	Output
3 3 0 0 0 0 4	3.00 0.00 0.00 4.00
5 10 5 4 8 0 8 4 5 -1 2	10.00 5.00 -1.00 2.00

Question 3 - Moving Rectangle

Define a struct representing a rectangle that are parallel to the axes in a Cartesian coordinate system. Represent a rectangle by its lower left and upper right endpoints using the Point you defined.

Write a function move which takes a rectangle pointer and two integers moveX and moveY representing the movement in the x and y axes respectively and moves the rectangle.

Example:

• Rectangle:
  • lower left point: (2, 0)
  • upper right point: (8, 4)
• moveX: -5
• moveY: 2
• Resulting Rectangle:
  • lower left point: (-3, 2)
  • upper right point: (3, 6)

Question 4 - Letter Grades

Define a struct representing a student having student_id (integer), mt_grade (integer), final_grade (integer) and letter_grade (char). The given program takes the grades of students and creates structs for students. You are supposed to calculate and set the letter grades of students using set_grade() function. The grade weights are 40%, 60% respectively and letter grades are as follows:

• 100-75: A
• 74-50: B
• 49-25: C
• 24-0: F

INPUT	OUTPUT
2 100 40 40 100	1000 B 1001 A
3 45 25 100 100 0 90	1000 C 1001 A 1002 B

#include <stdio.h>

// Fill the definition of the struct.
typedef struct{
  
} Student;

void set_grade(Student *p){

}

int main(void){
    int N;
    scanf("%d", &N);
    Student cmpe[N];
    int i;
    for(i = 0; i < N; i++){
      scanf("%d %d", &cmpe[i].mt_grade, &cmpe[i].final_grade);
      cmpe[i].student_id = 1000 + i;
      // Call set grade function
    }

    for(i = 0; i < N; i++)
        printf("%d %c\n", cmpe[i].student_id, cmpe[i].letter_grade);

    return 0;
}

Question 5 - Flights

Define a struct representing a flight which has following fields:

• Flight number
• Originating airport code (three characters)
• Destination airport code (three characters)
• Starting time
• Arrival time

Write a program which takes an integer N and then reads N flights. Then sorts the flights according to their starting time and the originating airport code.

Input	Output
4 3540 SAW ADB 14 15 3440 IST ESB 13 15 4041 ANT STL 13 21 4045 GTG KPG 17 18	4041 ANT STL 13 21 3440 IST ESB 13 15 3540 SAW ADB 14 15 4045 GTG KPG 17 18

Hint 1: Write a function which reads a flight from user.

Hint 2: Write a function for comparing two flights. It first checks the starting times and if they are equal then compares the originating airport codes. Funtion can return 1 if the first flight is greater, 0 if equal, -1 otherwise

Question 6 - Book Prices

Define a struct named: Book. Each book should have a name with exactly 3 letters (abbreviation). Each book should also have a page count (integer), and a price (integer).

Write a program which reads an integer n first, then read page counts, the names and prices of n books.

Write a function which takes an array of books, and sorts them according to their prices.

Using that function, your program should print the names and page counts of each book with the order of their prices. Like:

1. LOT: 528 pages (15 gold)
2. THG: 727 pages (32 gold)
3. MSB: 340 pages (120 gold)
4. etc..

Reading and printing format is up to you.

INPUT	OUTPUT
3 727 THG 32 528 LOT 15 340 MSB 120	LOT: 528 pages (15 gold) THG: 727 pages (32 gold) MSB: 340 pages (120 gold)

Question 7 - Smaller Better Faster Stronger (2018 Fall Final Q4)

Mossy Land's department of science and technology started a competition to find the rectangle with the smallest area. All the participants submitted their rectangles. Then a group of scientists calculated edge lengths of each rectangle and send them to you. Your task is to find the rectangle with the smallest area.

You will write a function (min_rectangle_area) that takes two parameters (a Rectangle array and an integer) then returns a Rectangle.

Input:

• The first line of the input contains: N (1 <= N <= 100) the number of rectangles.
• The next N lines contains 2 numbers that describes the edge lengths of each rectangle: edge_1 edge_2. (0 < edge_1, edge_2 < 100000)

Output:

• The area of the rectangle that has the smallest area.

INPUT	OUTPUT
2 2 5 3 4	10.00
3 4.2 2.1 1.8 5.3 2 8.2	8.82
8 12 684 485 684 48 542 158 48 564 12 21 188 126 441 1200 1450	3948.00
4 1.1 2.2 2.2 3.3 1.1 3.3 1.1 2.2	2.42

#include <stdio.h>

typedef struct rectangle{
    float edge1;
    float edge2;
}Rectangle;

// DO_NOT_EDIT_ANYTHING_ABOVE_THIS_LINE

// DO_NOT_EDIT_ANYTHING_BELOW_THIS_LINE

int main(){
    Rectangle r_min;
    int i;
    int N;
    Rectangle r[100];
    
    scanf("%d", &N);

    // Reads Rectangles
    for(i = 0 ; i < N ; i++)
        scanf("%f %f", &r[i].edge1, &r[i].edge2);
    
    r_min = min_rectangle_area(
    // DO_NOT_EDIT_ANYTHING_ABOVE_THIS_LINE

    // DO_NOT_EDIT_ANYTHING_BELOW_THIS_LINE
    );
    
    // Prints the area of the rectangle that has the smallest area
    printf("%.2f\n", r_min.edge1*r_min.edge2);
        
    return 0;
}