c_project/src/sorting.c at main · ryngpt/c_project · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
/**
 * @file sorting.c
 * @brief Implementations of sorting algorithms.
 *
 * Part of the C Learning & DSA Toolkit.
 */

#include "sorting.h"
#include <stddef.h>
#include <stdbool.h>

static void swap(int *a, int *b) {
    int temp = *a;
    *a = *b;
    *b = temp;
}

void bubble_sort(int arr[], int size) {
    if (arr == NULL || size <= 1) {
        return;
    }

    for (int i = 0; i < size - 1; i++) {
        bool swapped = false;

        for (int j = 0; j < size - i - 1; j++) {
            if (arr[j] > arr[j + 1]) {
                swap(&arr[j], &arr[j + 1]);
                swapped = true;
            }
        }

        if (!swapped) {
            break;
        }
    }
}

void selection_sort(int arr[], int size) {
    if (arr == NULL || size <= 1) {
        return;
    }

    for (int i = 0; i < size - 1; i++) {
        int min_idx = i;

        for (int j = i + 1; j < size; j++) {
            if (arr[j] < arr[min_idx]) {
                min_idx = j;
            }
        }

        if (min_idx != i) {
            swap(&arr[i], &arr[min_idx]);
        }
    }
}

void insertion_sort(int arr[], int size) {
    if (arr == NULL || size <= 1) {
        return;
    }

    for (int i = 1; i < size; i++) {
        int key = arr[i];
        int j = i - 1;

        while (j >= 0 && arr[j] > key) {
            arr[j + 1] = arr[j];
            j--;
        }
        arr[j + 1] = key;
    }
}

static void merge(int arr[], int left, int mid, int right) {
    int n1 = mid - left + 1;
    int n2 = right - mid;

    int left_arr[n1];
    int right_arr[n2];

    for (int i = 0; i < n1; i++) {
        left_arr[i] = arr[left + i];
    }
    for (int j = 0; j < n2; j++) {
        right_arr[j] = arr[mid + 1 + j];
    }

    int i = 0;
    int j = 0;
    int k = left;

    while (i < n1 && j < n2) {
        if (left_arr[i] <= right_arr[j]) {
            arr[k++] = left_arr[i++];
        } else {
            arr[k++] = right_arr[j++];
        }
    }

    while (i < n1) {
        arr[k++] = left_arr[i++];
    }

    while (j < n2) {
        arr[k++] = right_arr[j++];
    }
}

void merge_sort(int arr[], int left, int right) {
    if (arr == NULL || left >= right) {
        return;
    }

    int mid = left + (right - left) / 2;

    merge_sort(arr, left, mid);
    merge_sort(arr, mid + 1, right);
    merge(arr, left, mid, right);
}

static int partition(int arr[], int low, int high) {
    int pivot = arr[high];
    int i = low - 1;

    for (int j = low; j < high; j++) {
        if (arr[j] <= pivot) {
            i++;
            swap(&arr[i], &arr[j]);
        }
    }
    swap(&arr[i + 1], &arr[high]);
    return i + 1;
}

void quick_sort(int arr[], int low, int high) {
    if (arr == NULL || low >= high) {
        return;
    }

    int pi = partition(arr, low, high);

    quick_sort(arr, low, pi - 1);
    quick_sort(arr, pi + 1, high);
}