c-lang-hacker-rank.txt

c-lang-hacker-rank.c

# https://www.hackerrank.com/challenges/hello-world-c/problem

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

int main() 
{	
    char s[100];
    scanf("%[^\n]%*c", &s);

    /* Enter your code here. Read input from STDIN. Print output to STDOUT */    

    printf("Hello, World!\n");
    printf(s);

    return 0;
}


# https://www.hackerrank.com/challenges/conditional-statements-in-c/problem

#include <assert.h>
#include <limits.h>
#include <math.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

char* readline();

int main()
{
    char* n_endptr;
    char* n_str = readline();
    int n = strtol(n_str, &n_endptr, 10);

    if (n_endptr == n_str || *n_endptr != '\0') { exit(EXIT_FAILURE); }

    // Write Your Code Here

    if (n == 1) {
        printf("one");
    } else if (n == 2) {
        printf("two");
    } else if (n == 3) {
        printf("three");
    } else if (n == 4) {
        printf("four");
    } else if (n == 5) {
        printf("five");
    } else if (n == 6) {
        printf("six");
    } else if (n == 7) {
        printf("seven");
    } else if (n == 8) {
        printf("eight");
    } else if (n == 9) {
        printf("nine");
    } else {
        printf("Greater than 9");
    }

    return 0;
}

char* readline() {
    size_t alloc_length = 1024;
    size_t data_length = 0;
    char* data = malloc(alloc_length);

    while (true) {
        char* cursor = data + data_length;
        char* line = fgets(cursor, alloc_length - data_length, stdin);

        if (!line) { break; }

        data_length += strlen(cursor);

        if (data_length < alloc_length - 1 || data[data_length - 1] == '\n') { break; }

        size_t new_length = alloc_length << 1;
        data = realloc(data, new_length);

        if (!data) { break; }

        alloc_length = new_length;
    }

    if (data[data_length - 1] == '\n') {
        data[data_length - 1] = '\0';
    }

    data = realloc(data, data_length);

    return data;
}


# https://www.hackerrank.com/challenges/playing-with-characters/problem

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

int main() 
{
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */
    char c;
    scanf("%c", &c);
    printf("%c", c);

    scanf("\n");
    printf("\n");

    char s[500];
    scanf("%[^\n]%*c", s);
    printf(s);

    scanf("\n");
    printf("\n");

    char sent[500];
    scanf("%[^\n]%*c", sent);
    printf(sent);

    
    return 0;
}


# https://www.hackerrank.com/challenges/for-loop-in-c/problem

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

int main() 
{
    int a, b;
    scanf("%d\n%d", &a, &b);
    
    for (int i = a; i <= b; i++) {
        printProperly(i);
    }

    return 0;
}

void printProperly(int n) {
    if (n == 1) {
        printf("one\n");
    } else if (n == 2) {
        printf("two\n");
    } else if (n == 3) {
        printf("three\n");
    } else if (n == 4) {
        printf("four\n");
    } else if (n == 5) {
        printf("five\n");
    } else if (n == 6) {
        printf("six\n");
    } else if (n == 7) {
        printf("seven\n");
    } else if (n == 8) {
        printf("eight\n");
    } else if (n == 9) {
        printf("nine\n");
    } else if (n % 2 == 0) {
        printf("even\n");
    } else {
        printf("odd\n");
    }
}


# https://www.hackerrank.com/challenges/sum-of-digits-of-a-five-digit-number/problem

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

int getIntLen(int number);

int main() {    
    int n;
    scanf("%d", &n);

    //Complete the code to calculate the sum of the five digits on n.

    int inputLen = getIntLen(n);

    int counter = 0;
    int divisor = 10;

    for (int i = 0; i < inputLen; i++) {
        int number = ((n % divisor) - counter) / (divisor/10);
        printf("%d\n", number);
        counter += number;
        divisor *= 10;
    }

    printf("%d\n", counter);

    return 0;
}

int getIntLen(int number) {
    int count = 0;

    while (number > 0) {
        number /= 10;
        count++;
    }

    return count;
}


# https://www.hackerrank.com/challenges/bitwise-operators-in-c/problem

#include <stdio.h>
#include <string.h>
#include <math.h>
#include <stdlib.h>
//Complete the following function.

void calculate_the_maximum(int n, int k) {
    //Write your code here.

    int maxAndLessThenK = 0;
    int maxOrLessThenK = 0;
    int maxXorLessThenK = 0;

    for (int i = 1; i < n; i++) {
        for (int j = i + 1; j <= n; j++) {
            int aAndB = i & j;
            int aOrB = i | j;
            int aXorB = i ^ j;

            if (aAndB < k && aAndB > maxAndLessThenK) {
                maxAndLessThenK = aAndB;
            }

            if (aOrB < k && aOrB > maxOrLessThenK) {
                maxOrLessThenK = aOrB;
            }

            if (aXorB < k && aXorB > maxXorLessThenK) {
                maxXorLessThenK = aXorB;
            }
        }
    }

    printf("%d\n", maxAndLessThenK);
    printf("%d\n", maxOrLessThenK);
    printf("%d\n", maxXorLessThenK);
}

int main() {
    int n, k;
  
    scanf("%d %d", &n, &k);
    calculate_the_maximum(n, k);
 
    return 0;
}


# https://www.hackerrank.com/challenges/printing-pattern-2/problem

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

int main() 
{
    int n;
    scanf("%d", &n);
    // Complete the code to print the pattern.

    int sizeOfSquare = n * 2 - 1;

    //  y
    //  y
    //  y
    //  y
    // yx x x x x

    // 3 3 3 3 3
    // 3 2 2 2 3 
    // 3 2 1 2 3
    // 3 2 2 2 3
    // 3 3 3 3 3

    for (int yAxis = 0; yAxis < sizeOfSquare; yAxis++) {
        for (int xAxis = 0; xAxis < sizeOfSquare; xAxis++) {
            int valueToPrint = n;

            // 1st 2nd
            // 3rd 4th

            // 1st little square
            if (xAxis <= floor(sizeOfSquare/2) && yAxis <= floor(sizeOfSquare/2)) {
                if (xAxis > yAxis) {
                    valueToPrint -= yAxis;
                } else {
                    valueToPrint -= xAxis;
                }
            }

            // 2nd little square
            if (xAxis > floor(sizeOfSquare/2) && yAxis <= floor(sizeOfSquare/2)) {
                if (yAxis < sizeOfSquare - xAxis) {
                    valueToPrint -= yAxis;
                } else {
                    valueToPrint -= sizeOfSquare - 1 - xAxis;
                }
            }

            // 3rd little square
            if (xAxis <= floor(sizeOfSquare / 2) && yAxis > floor(sizeOfSquare/2)) {
                if (xAxis < sizeOfSquare - yAxis) {
                    valueToPrint -= xAxis;
                } else {
                    valueToPrint -= sizeOfSquare - 1 - yAxis;
                }
            }

            // 4th little square
            if (xAxis > floor(sizeOfSquare/2) && yAxis > floor(sizeOfSquare/2)) {
                if (xAxis > yAxis) {
                    valueToPrint -= sizeOfSquare - 1 - xAxis;
                } else {
                    valueToPrint -= sizeOfSquare - 1 - yAxis;
                }
            }

            printf("%d ", valueToPrint);
        }

        printf("\n");
    }

    return 0;
}


# https://www.hackerrank.com/challenges/1d-arrays-in-c/problem

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

int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */    
    int n;

    scanf("%d", &n);

    int sum = 0;

    // An array is a container object that holds a fixed number of values of a single type.
    // To create an array in C, we can do int arr[n];. Here, arr, is a variable array which
    // holds up to  integers. The above array is a static array that has memory allocated at 
    // compile time. A dynamic array can be created in C, using the malloc function and the
    // memory is allocated on the heap at runtime. To create an integer array,  of size ,
    // int *arr = (int*)malloc(n * sizeof(int)), where  points to the base address of the array.

    // In this challenge, you have to create an array of size  dynamically, input the elements of
    // the array, sum them and print the sum of the elements in a new line.


    // // static array that has memory allocated at compile time at the stack
    // int arr[n];

    // allocates memory on runtime on the heap
    int *arr = (int*)malloc(n * sizeof(int));

    for (int i = 0; i < n; i++) {
        scanf("%d", &arr[i]);
    }

    for (int j = 0; j < n; j++) {
        sum += arr[j];
    }

    printf("%d", sum);

    return 0;
}


# https://www.hackerrank.com/challenges/reverse-array-c/problem

#include <stdio.h>
#include <stdlib.h>

int main()
{
    int num, *arr, i;
    scanf("%d", &num);
    arr = (int*) malloc(num * sizeof(int));
    for(i = 0; i < num; i++) {
        scanf("%d", arr + i);
    }

    /* Write the logic to reverse the array. */

    for(i = num - 1; i >= 0; i--)
        printf("%d ", *(arr + i));
    return 0;
}


# https://www.hackerrank.com/challenges/printing-tokens-/forum
# v1

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

int main() {
    char *s;
    s = malloc(1024 * sizeof(char));
    scanf("%[^\n]", s);

    s = realloc(s, strlen(s) + 1);
    //Write your logic to print the tokens of the sentence here.

    int last = 0;

    for (int i = 0; i < strlen(s); i++) {

        if (s[i] == ' ' || i == strlen(s) - 1) {
            char str[strlen(s)];

            memset(&str, 0, strlen(s));

            int jPointer = last;

            for (int j = 0; j <= i - last; j++) {
                if (s[jPointer] != ' ') {
                    str[j] = s[jPointer];
                }

                jPointer++;
            }

            last = i + 1;

            if (str[0] != 0) {
                printf("%s\n", str);
            }
        }
    }

    return 0;
}

# v2

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

int main() {
    char *s;
    s = malloc(1024 * sizeof(char));
    scanf("%[^\n]", s);

    s = realloc(s, strlen(s) + 1);
    //Write your logic to print the tokens of the sentence here.

    char *p = s;

    int lastWasSpace = 0;

    while (*p != '\0') {
        if (*p != ' ') {
            printf("%c", *p);
            lastWasSpace = 0;
        } else if (!lastWasSpace) {
            printf("\n");
            lastWasSpace = 0;
        }

        p++;
    }

    return 0;
}

# v3

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

int main() {
    char *s;
    s = malloc(1024 * sizeof(char));
    scanf("%[^\n]", s);

    s = realloc(s, strlen(s) + 1);
    //Write your logic to print the tokens of the sentence here.

    for (char * j = s; *j != '\0'; j++) {
        if (*j == ' ') {
            *j = '\n';
        }
    }

    printf("%s", s);

    return 0;
}


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