Week 4 Code Examples

0.arrays/numbers_functions.c

// Week 4 Lecture example
// Using arrays with functions

#include <stdio.h>
#define DATA_SIZE 6

void read_data(int size, int array[]);
void print_data(int size, int array[]);
void print_odd_data(int size, int array[]);
int find_maximum(int size, int array[]);
 
int main(void) {
    int data[DATA_SIZE];
    
    printf("Enter 6 integers: ");
    read_data(DATA_SIZE, data);
    print_data(DATA_SIZE, data);
    print_odd_data(DATA_SIZE, data);
    int max = find_maximum(DATA_SIZE, data);
    printf("Max: %d\n", max);
    return 0;
}

int find_maximum(int size, int array[]) {
    int max = array[0];
    int i = 1; 
    while (i < size) {
        if (array[i] > max) {
            max = array[i];
        }
        i++;
    }
    return max;
}

void print_odd_data(int size, int array[]){
    int i = 0;
    while (i < size) {
        if (array[i] % 2 != 0) {
            printf("%d ", array[i]);
        }
        i++;
    }
    printf("\n");
}

//scan numbers into the array
void read_data(int size, int array[]) { 
    int i = 0;
    while (i < size) {
        scanf("%d", &array[i]);
        i++;
    }
}

// Print the array
void print_data(int size, int array[]){  
    int i = 0;
    while (i < size) {
        printf("%d ", array[i]);
        i++;
    }
    printf("\n");
}

 

0.arrays/struct_array.c

// Week 4 example
// Using arrays of structs

#include <stdio.h>
#define MAP_SIZE 5

struct coordinate {
    int x;
    int y;
};


void read_map(int size, struct coordinate map[]);
void print_map(int size, struct coordinate map[]);
void translate_x(int size, struct coordinate map[], int amount);


int main(void) {
    struct coordinate map[MAP_SIZE];
    read_map(MAP_SIZE, map);
    print_map(MAP_SIZE, map);
    translate_x(MAP_SIZE, map, 2);
    print_map(MAP_SIZE, map);
    return 0;
}

void translate_x(int size, struct coordinate map[], int amount){
    int i = 0;
    while (i < size) {
        map[i].x =  map[i].x + amount;
        i++;
    }
}
 
void read_map(int size, struct coordinate map[]){
    int i = 0;
    while (i < size) {
        scanf("%d %d", &map[i].x, &map[i].y);
        i++;
    }
}

void print_map(int size, struct coordinate map[]){
    int i = 0;
    while (i < size) {
        printf("(%d, %d)", map[i].x, map[i].y);
        i++;
    }
    printf("\n");
}

1.2D_arrays/2D_array.c

#include <stdio.h>
#define ROWS 2
#define COLS 3

void print_grid(int grid[ROWS][COLS]);
void scan_grid(int grid[ROWS][COLS]);
int sum_grid(int grid[ROWS][COLS]);
void print_row_sums(int grid[ROWS][COLS]);
void print_col_sums(int grid[ROWS][COLS]);

int main(void) {
    int grid[ROWS][COLS] =  {{3, 5, 1},
                            {2, 4, 9}};
    
    // int row;
    // int col;
    // printf("Enter a row and col: ");
    // scanf("%d %d", &row, &col);
    // printf("Value: %d\n", grid[row][col]);
    print_grid(grid);
    //scan_grid(grid);
    //print_grid(grid);
    int sum = sum_grid(grid);
    printf("Sum is %d\n", sum);
    print_row_sums(grid);
    print_col_sums(grid);
    return 0;
}

void print_grid(int grid[ROWS][COLS]) {
    printf("Grid\n");
    int row = 0;
    while (row < ROWS) {
        int col = 0;
        while (col < COLS) {
            printf("%d ", grid[row][col]);
            col++;
        }
        printf("\n");
        row++;
    }
}

void scan_grid(int grid[ROWS][COLS]) {
    printf("Please enter data\n");
    int row = 0;
    while (row < ROWS) {
        int col = 0;
        while (col < COLS) {
            scanf("%d", &grid[row][col]);
            col++;
        }
        row++;
    }
}

int sum_grid(int grid[ROWS][COLS]) {
    int sum = 0;
    int row = 0;
    while (row < ROWS) {
        int col = 0;
        while (col < COLS) {
            sum = sum + grid[row][col];
            col++;
        }
        row++;
    }
    return sum;
}

void print_row_sums(int grid[ROWS][COLS]){
    int row = 0;
    while (row < ROWS) {
        int col = 0;
        int sum = 0;
        while (col < COLS) {
            sum = sum + grid[row][col];
            col++;
        }
        printf("Sum of row %d is %d\n", row, sum);
        row++;
    }
}

void print_col_sums(int grid[ROWS][COLS]){
    int col = 0;
    while (col < COLS) {
        int row = 0;
        int sum = 0;
        while (row < ROWS) {
            sum = sum + grid[row][col];
            row++;
        }
        printf("Sum of col %d is %d\n", col, sum);
        col++;
    }
}

1.2D_arrays/diagonals.c

#include <stdio.h>
#define SIZE 4

int sum_diagonal_top_left(int grid[SIZE][SIZE]);
int sum_diagonal_top_right(int grid[SIZE][SIZE]);

int main(void) {
    int grid[SIZE][SIZE] = {{3, 5, 1, 2},
                            {2, 4, 9, 8},
                            {6, 0, 2, 7},
                            {4, 1, 6, 5}};

    printf("The sum diagonal top left %d\n", sum_diagonal_top_left(grid));
    printf("The sum diagonal top right %d\n", sum_diagonal_top_right(grid));
   
    return 0;
}

int sum_diagonal_top_left(int grid[SIZE][SIZE]){
    int sum = 0;
    int i = 0;
    while (i < SIZE) {
        sum = sum + grid[i][i];
        i++;
    }
    return sum;
}

// int sum_diagonal_top_left(int grid[SIZE][SIZE]){
//     int sum = 0;
//     int row = 0;
//     while (row < SIZE) {
//         int col = 0;
//         while (col < SIZE) {
//             if (row == col) {
//                 sum = sum + grid[row][col];
//             }
//             col++;
//         }
//         row++;
//     }
//     return sum;
// }
 
int sum_diagonal_top_right(int grid[SIZE][SIZE]){
    int sum = 0;
    int i = 0;
    while (i < SIZE) {
        sum = sum + grid[i][SIZE - i - 1];
        i++;
    }
    return sum;
}
 

1.2D_arrays/recap_2D_array.c

#include <stdio.h>
#define ROWS 3
#define COLS 2

void print_grid(int grid[ROWS][COLS]);
void copy_grid(int grid[ROWS][COLS], int grid_copy[ROWS][COLS]);

int main(void) {
    int grid1[ROWS][COLS] =  {{2, 9},
                              {5, 1},
                              {8, 0}};
    
    int grid2[ROWS][COLS];

    copy_grid(grid1, grid2);

    printf("Grid 1\n");
    print_grid(grid1);
    printf("\nGrid 2\n");
    print_grid(grid2);

    return 0;
}

void copy_grid(int grid[ROWS][COLS], int grid_copy[ROWS][COLS]){
    int row = 0;
    while (row < ROWS) {
        int col = 0;
        while (col < COLS) {
            grid_copy[row][col] = grid[row][col];
            col++;
        }
        row++;
    }
}

void print_grid(int grid[ROWS][COLS]) {
    int row = 0;
    while (row < ROWS) {
        int col = 0;
        while (col < COLS) {
            printf("%d ", grid[row][col]);
            col++;
        }
        printf("\n");
        row++;
    }
}

2.strings/read_strings.c

// Lecture example for COMP1511/1911 Week 4
// Some simple examples demonstrating how strings work in C

#include <stdio.h>
#include <ctype.h>

#define MAX 20

void capitalise(char s[]);


int main(void) {
    char movie[MAX];
    printf("Type in your favourite movies: ");
    while (fgets(movie, MAX, stdin) != NULL){
        printf("%s\n",movie);
        capitalise(movie);
        printf("%s\n",movie);
    }
    
    return 0;
}

// convert every lowercase character in the given string, s to uppercase
void capitalise(char s[]) {
    int i = 0;
    while (s[i] != '\0') {
        s[i] = toupper(s[i]);
        i++;
    }
}

    

2.strings/simple_strings.c

// Lecture example for COMP1511/1911 Week 4 
// Some simple examples demonstrating how strings work in C 

#include <stdio.h>

#define MAX_LEN 100

int main(void) {
    // What do these look like in memory
    char favourite_food[] = {'k', 'f', 'c', '\0'}; 
    char favourite_drink[] = "kombucha";
    char favourite_book[MAX_LEN] = "Folk of the Faraway Tree";

    // Can print out characters
    printf("%c\n",favourite_food[0]);
    printf("%c\n",favourite_drink[3]);

    // Can print out the whole string
    printf("%s\n", favourite_food);
    printf("%s\n", favourite_drink);
    printf("%s\n", favourite_book);
    
    favourite_drink[0] = 'Z';
    printf("%s\n", favourite_drink);
    
    favourite_drink[4] = '\0';
    printf("%s\n", favourite_drink);
    
    favourite_food[3] = 'd';
    printf("%s\n", favourite_food);
    
    //favourite_book = "Programming in C";

    // How do you think we read them in?
    
    return 0;
}

2.strings/string_functions.c

// Example of using string functions from string.h library
// strings can get a bit tricky and messy in C
// It is easy to overflow buffers or lose our '\0' characters!

#include <stdio.h>
#include <string.h>

#define MAX_LENGTH 100

int main(void) {
    // Declare an array to store a string
    char puppy[MAX_LENGTH] = "Boots";

    printf("%s\n", puppy);
 
    // Copy the string "Finn" into the word array
    // Make sure your array is big enough!!!
    
    strcpy(puppy, "Finn");
    printf("%s\n", puppy);

    // Find string length. It does NOT include '\0' in the length
    int len = strlen(puppy);
    printf("%s has length %d\n", puppy, len);


    // Declare an array to store a string
    // char name[] = "Oscar";

    // if (strcmp(name, "Oscar") == 0) {
    //     printf("Hi Oscar\n");
    // } else {
    //     printf("You are not Oscar!\n");
    // }

    // if (strcmp(name, "Edgar") == 0) {
    //     printf("Hi Edgar\n");
    // } else {
    //     printf("You are not Edgar!\n");
    // }

    // if (strcmp(name, "Edgar") < 0) {
    //     printf("%s Edgar\n", name);
    // } else {
    //     printf("Edgar %s\n", name);
    // }

/*
    // Declare an array to store a string
    char name2[MAX_LENGTH];
    printf("\nType in a name: ");

    // Read in a string
    fgets(name2, MAX_LENGTH, stdin);

    // Use strcmp to compare 2 strings
    if (strcmp("Oscar", name2) == 0) {
        printf("Yay Oscar!\n");
    }
*/
    return 0;
}