leetcode/sort.cpp at main · Aqiu16717/leetcode · 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
147
148
149
150
151
152
153
154
155
156
157
158
159
#include <algorithm>
#include <cassert>
#include <iostream>
#include <vector>

static void EXPECT_VECTOR_EQ(const std::vector<int>& v1,
                             const std::vector<int>& v2) {
    assert(v1.size() == v2.size());
    for (int i = 0; i < v1.size(); ++i) {
        assert(v1[i] == v2[i]);
    }
    std::cout << "PASSED" << std::endl;
}

class Sort {
public:
    void bubble_sort(std::vector<int>& nums) {
        int n = nums.size();
        bool flag = false;
        for (int i = n - 1; i > 0; --i) {
            for (int j = 0; j < i; ++j) {
                if (nums[j] > nums[j + 1]) {
                    flag = true;
                    std::swap(nums[j], nums[j + 1]);
                }
            }
            if (!flag) {
                break;
            }
        }
    }

    void selection_sort(std::vector<int>& nums) {
        for (int i = 0; i < nums.size() - 1; ++i) {
            int min_idx = i;
            for (int j = i + 1; j < nums.size(); ++j) {
                if (nums[j] < nums[min_idx]) {
                    min_idx = j;
                }
            }
            std::swap(nums[i], nums[min_idx]);
        }
    }

    void insertion_sort(std::vector<int>& nums) {
        int n = nums.size();
        for (int i = 1; i < n; ++i) {
            int tmp = nums[i];
            int j = i - 1;
            while (j >= 0 && nums[j] > tmp) {
                nums[j + 1] = nums[j];
                --j;
            }
            nums[j + 1] = tmp;
        }
    }
    /**
     * 27, 85, 12, 43, 68, 91, 34, 57, 6, 74
     * i                                   j
     * p
     *                                 j
     *     i
     * 27, 6, 12, 43, 68, 91, 34, 57, 85, 74
     *         j
     *         i
     */

    void quick_sort(std::vector<int>& nums, int low, int high) {
        if (low < high) {
            int i = low;
            int j = high;
            int pivot = nums[low];
            while (i < j) {
                while (i < j && nums[j] >= pivot) {
                    --j;
                }
                while (i < j && nums[i] <= pivot) {
                    ++i;
                }
                std::swap(nums[i], nums[j]);
            }
            nums[i] = pivot;
            quick_sort(nums, low, i - 1);
            quick_sort(nums, i + 1, high);
        }
    }

    void merge_sort(std::vector<int>& nums, int left, int right) {
        if (left >= right) {
            return;
        }
        int mid = left + (right - left) / 2;
        merge_sort(nums, left, mid);
        merge_sort(nums, mid + 1, right);
        merge(nums, left, mid, right);
        std::vector<int> tmp(right - left + 1);
    }
    void merge(std::vector<int> &nums, int left, int mid, int right) {
    }
};

static void printVec(const std::vector<int>& vec) {
    for (auto elem : vec) {
        std::cout << elem << "\t";
    }
    std::cout << "\n";
}

void test_bubble_sort() {
    std::cout << __func__ << std::endl;
    Sort s;
    std::vector<int> nums = {27, 85, 12, 43, 68, 91, 34, 57, 6, 74};
    // std::cout << "before" << std::endl;
    // printVec(nums);
    s.bubble_sort(nums);
    // std::cout << "after" << std::endl;
    // printVec(nums);
    EXPECT_VECTOR_EQ(nums, {6, 12, 27, 34, 43, 57, 68, 74, 85, 91});
}

void test_selection_sort() {
    std::cout << __func__ << std::endl;
    Sort s;
    std::vector<int> nums = {27, 85, 12, 43, 68, 91, 34, 57, 6, 74};
    // std::cout << "before" << std::endl;
    // printVec(nums);
    s.selection_sort(nums);
    // std::cout << "after" << std::endl;
    EXPECT_VECTOR_EQ(nums, {6, 12, 27, 34, 43, 57, 68, 74, 85, 91});
    // printVec(nums);
}

void test_insertion_sort() {
    std::cout << __func__ << std::endl;
    Sort s;
    std::vector<int> nums = {27, 85, 12, 43, 68, 91, 34, 57, 6, 74};
    s.insertion_sort(nums);
    EXPECT_VECTOR_EQ(nums, {6, 12, 27, 34, 43, 57, 68, 74, 85, 91});
}

void test_quick_sort() {
    std::cout << __func__ << std::endl;
    Sort s;
    std::vector<int> nums = {27, 85, 12, 43, 68, 91, 34, 57, 6, 74};
    s.quick_sort(nums, 0, nums.size() - 1);
    EXPECT_VECTOR_EQ(nums, {6, 12, 27, 34, 43, 57, 68, 74, 85, 91});
}

void run_test() {
    test_bubble_sort();
    test_selection_sort();
    test_insertion_sort();
    test_quick_sort();
}

int main() {
    run_test();
    return 0;
}