归并排序模板-优快云博客

本文链接：https://blog.youkuaiyun.com/m0_49824320/article/details/120820287

void merge_sort(int q[], int l, int r) 
{
    if(l >= r) return;
    int mid = l + r >> 1;
    merge_sort(q, l, mid);
    merge_sort(q, mid + 1, r);
    int i = l, j = mid + 1, k = 0;
    while(i <= mid && j <= r) 
    {
        if(q[i] <= q[j]) tmp[k++] = q[i++];
        else tmp[k++] = q[j++];
    }
    while(i <= mid) tmp[k++] = q[i++];
    while(j <= r) tmp[k++] = q[j++];
    for(i = l, j = 0; i <= r; i++, j++) q[i] = tmp[j];
}

对应题目

787. 归并排序 - AcWing题库

#include<iostream>
using namespace std;
const int N = 1e5 + 5;
int n;
int q[N], tmp[N];

void merge_sort(int q[], int l, int r) 
{
    if(l >= r) return;
    int mid = l + r >> 1;
    merge_sort(q, l, mid);
    merge_sort(q, mid + 1, r);
    int i = l, j = mid + 1, k = 0;
    while(i <= mid && j <= r) 
    {
        if(q[i] <= q[j]) tmp[k++] = q[i++];
        else tmp[k++] = q[j++];
    }
    while(i <= mid) tmp[k++] = q[i++];
    while(j <= r) tmp[k++] = q[j++];
    for(i = l, j = 0; i <= r; i++, j++) q[i] = tmp[j];
}

int main() 
{
    scanf("%d", &n);
    for(int i = 0; i < n; i++) scanf("%d", &q[i]);
    merge_sort(q, 0, n - 1);
    for(int i = 0; i < n; i++) printf("%d ", q[i]);
    return 0;
}

c语言版本

#include<stdio.h>
#define N 100005
int i, n;
int q[N], tmp[N];

void merge_sort(int q[], int l, int r)
{
    if(l >= r) return;
    int mid = l + r >> 1;
    merge_sort(q, l, mid);
    merge_sort(q, mid + 1, r);
    int i = l, j = mid + 1, k = 0;
    while(i <= mid && j <= r)
    {
        if(q[i] <= q[j]) tmp[k++] = q[i++];
        else tmp[k++] = q[j++];
    }
    while(i <= mid) tmp[k++] = q[i++];
    while(j <= r) tmp[k++] = q[j++];
    for(i = l, j = 0; i <= r; i++, j++) q[i] = tmp[j];
}

int main()
{
    scanf("%d", &n);
    for(i = 0; i < n; i++) scanf("%d", &q[i]);
    merge_sort(q, 0, n - 1);
    for(i = 0; i < n; i++) printf("%d ", q[i]);
    return 0;
}