C: تطبيق： المصفوفات والدوال

#include <stdio.h>

void bubble_sort(int *arr, int len) {
    int i, j;
    int swapped;

    for (i = 0; i < len - 1; i++) {
        swapped = 0;
        for (j = 0; j < len - 1 - i; j++) {
            if (arr[j] > arr[j + 1]) {
                int temp = arr[j];
                arr[j] = arr[j + 1];
                arr[j + 1] = temp;
                swapped = 1;
            }
        }
        if (!swapped) break;
    }
}

void print_array(const int *arr, int len) {
    int i;
    for (i = 0; i < len; i++) {
        printf("%d ", arr[i]);
    }
    printf("\n");
}

int main(void) {
    int data[] = {64, 34, 25, 12, 22, 11, 90};
    int len = sizeof(data) / sizeof(data[0]);

    printf("Before: ");
    print_array(data, len);

    bubble_sort(data, len);

    printf("After:  ");
    print_array(data, len);

    return 0;
}

Before: 64 34 25 12 22 11 90
After:  11 12 22 25 34 64 90

#include <stdio.h>

void sort_desc(int *arr, int len) {
    int i, j, swapped;
    for (i = 0; i < len - 1; i++) {
        swapped = 0;
        for (j = 0; j < len - 1 - i; j++) {
            if (arr[j] < arr[j + 1]) {
                int temp = arr[j];
                arr[j] = arr[j + 1];
                arr[j + 1] = temp;
                swapped = 1;
            }
        }
        if (!swapped) break;
    }
}

int main(void) {
    int scores[] = {85, 92, 78, 95, 88};
    int len = sizeof(scores) / sizeof(scores[0]);
    int i;

    sort_desc(scores, len);
    printf("Ranking: ");
    for (i = 0; i < len; i++) {
        printf("%d ", scores[i]);
    }
    printf("\n");
    return 0;
}

Ranking: 95 92 88 85 78

#include <stdio.h>

int binary_search(const int *arr, int len, int target) {
    int low = 0;
    int high = len - 1;

    while (low <= high) {
        int mid = low + (high - low) / 2;

        if (arr[mid] == target) {
            return mid;
        } else if (arr[mid] < target) {
            low = mid + 1;
        } else {
            high = mid - 1;
        }
    }

    return -1;
}

int main(void) {
    int data[] = {2, 5, 8, 12, 16, 23, 38, 45, 56, 78};
    int len = sizeof(data) / sizeof(data[0]);
    int targets[] = {23, 7, 78, 1};
    int num = sizeof(targets) / sizeof(targets[0]);
    int i;

    for (i = 0; i < num; i++) {
        int pos = binary_search(data, len, targets[i]);
        if (pos >= 0) {
            printf("%d found at index %d\n", targets[i], pos);
        } else {
            printf("%d not found\n", targets[i]);
        }
    }
    return 0;
}

23 found at index 5
7 not found
78 found at index 9
1 not found

#include <stdio.h>

int lower_bound(const int *arr, int len, int target) {
    int low = 0;
    int high = len;
    while (low < high) {
        int mid = low + (high - low) / 2;
        if (arr[mid] < target) {
            low = mid + 1;
        } else {
            high = mid;
        }
    }
    return low;
}

int main(void) {
    int data[] = {1, 3, 3, 5, 7, 7, 7, 9, 11};
    int len = sizeof(data) / sizeof(data[0]);
    int pos = lower_bound(data, len, 7);
    printf("First >= 7 at index %d, value=%d\n", pos, data[pos]);
    return 0;
}

First >= 7 at index 4, value=7

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

void str_reverse(char *s) {
    char *left = s;
    char *right = s + strlen(s) - 1;

    while (left < right) {
        char temp = *left;
        *left = *right;
        *right = temp;
        left++;
        right--;
    }
}

int main(void) {
    char s1[] = "Hello World";
    char s2[] = "ABCDE";
    char s3[] = "racecar";

    str_reverse(s1);
    str_reverse(s2);
    str_reverse(s3);

    printf("%s\n", s1);
    printf("%s\n", s2);
    printf("%s\n", s3);

    return 0;
}

dlroW olleH
EDCBA
racecar

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

int is_palindrome(const char *s) {
    const char *left = s;
    const char *right = s + strlen(s) - 1;
    while (left < right) {
        while (left < right && !isalnum((unsigned char)*left)) left++;
        while (left < right && !isalnum((unsigned char)*right)) right--;
        if (tolower((unsigned char)*left) != tolower((unsigned char)*right)) {
            return 0;
        }
        left++;
        right--;
    }
    return 1;
}

int main(void) {
    printf("%d\n", is_palindrome("racecar"));
    printf("%d\n", is_palindrome("hello"));
    printf("%d\n", is_palindrome("A man a plan a canal Panama"));
    return 0;
}

1
0
1

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

void char_freq(const char *s, int *freq, int size) {
    int i;
    for (i = 0; i < size; i++) freq[i] = 0;
    while (*s != '\0') {
        unsigned char ch = (unsigned char)*s;
        if (ch < (unsigned)size) freq[ch]++;
        s++;
    }
}

int main(void) {
    char text[] = "Hello World!";
    int freq[256] = {0};
    int i;

    char_freq(text, freq, 256);

    for (i = 32; i < 127; i++) {
        if (freq[i] > 0) printf("'%c': %d  ", i, freq[i]);
    }
    printf("\n");
    return 0;
}

' ': 1  '!': 1  'H': 1  'W': 1  'd': 1  'e': 1  'l': 3  'o': 2  'r': 1

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

void letter_freq(const char *s, int *freq) {
    int i;
    for (i = 0; i < 26; i++) freq[i] = 0;
    while (*s != '\0') {
        if (isalpha((unsigned char)*s)) {
            freq[tolower((unsigned char)*s) - 'a']++;
        }
        s++;
    }
}

char find_max(const int *freq, int size) {
    int max_idx = 0;
    int i;
    for (i = 1; i < size; i++) {
        if (freq[i] > freq[max_idx]) max_idx = i;
    }
    return 'a' + max_idx;
}

int main(void) {
    const char *text = "The quick brown fox jumps over the lazy dog";
    int freq[26];
    letter_freq(text, freq);
    char max_ch = find_max(freq, 26);
    printf("Most frequent letter: %c (%d times)\n", max_ch, freq[max_ch - 'a']);
    return 0;
}

Most frequent letter: o (4 times)