C++ 归并排序算法实现

void merge_sort(vector<int> &data, int start, int end) {
if (start < end) {
int mid = (start + end) / 2;
merge_sort(data, start, mid);
merge_sort(data, mid + 1, end);
merge(data, start, mid, end);
}
}

void merge(vector<int> &data, int start, int mid, int end) {
vector<int> tmp;
int i = start, j = mid + 1;
while (i != mid + 1 && j != end + 1) {
if (data[i] <= data[j]) {
tmp.push_back(data[i++]);
} else {
tmp.push_back(data[j++]);
}
}
while (i != mid + 1) {
tmp.push_back(data[i++]);
}
while (j != end + 1) {
tmp.push_back(data[j++]);
}
for (int i = 0; i < tmp.size(); i++) {
data[start + i] = tmp[i];
}
}

#include <iostream>
#include <vector>
using namespace std;

//函数声明
void merge_sort(vector<int> &data, int start, int end);
void merge(vector<int> &data, int start, int mid, int end);
void output_array(vector<int> &data);   //输出

void merge_sort(vector<int> &data, int start, int end) {
if (start < end) {
int mid = (start + end) / 2;
merge_sort(data, start, mid);
merge_sort(data, mid + 1, end);
merge(data, start, mid, end);
}
}

void merge(vector<int> &data, int start, int mid, int end) {
vector<int> tmp;
int i = start, j = mid + 1;
while (i != mid + 1 && j != end + 1) {
if (data[i] <= data[j]) {
tmp.push_back(data[i++]);
} else {
tmp.push_back(data[j++]);
}
}
while (i != mid + 1) {
tmp.push_back(data[i++]);
}
while (j != end + 1) {
tmp.push_back(data[j++]);
}
for (int i = 0; i < tmp.size(); i++) {
data[start + i] = tmp[i];
}
}

void output_array(vector<int> &data) {
for(auto i : data) {
cout << i << " ";
}
cout << endl;
}

int main() {
int _data[] = {2, 4, 6, 0, 9, 8};
vector<int> data(_data, _data + 6);
merge_sort(data, 0, (int)data.size() - 1);
output_array(data);
return 0;
}