排序算法代码总结

代码包含：
1. 随机化函数
2. 快速排序
3. 归并排序
4. 堆排序
代码进行了一些精简，方便做题时应用

#include<ctime>#include<cstdlib>#include<cstdio>#include<iostream>using namespace std;int a[20000], b[20000], c[20000], h[20000], q[20000];void quick_sort(int a[], int l, int r){    if (l >= r) return;    int i = l, j = r, x = a[l];    while(i < j){        while (i < j && a[j] >= x)j--;        if (i < j)a[i++] = a[j];        while(i < j && a[i] < x)i++;        if (i < j)a[j--] = a[i];    }    a[i] = x;    quick_sort(a, l, i-1);    quick_sort(a, i+1, r);}void merge_sort(int b[], int l, int r){    if (l >= r)return;    int mid = (l+r)>>1;    merge_sort(b, l, mid);    merge_sort(b, mid+1, r);    int i = l, j = mid+1, tot = 0;    while(i <= mid && j <= r) if (b[i] <= b[j])c[tot++] = b[i++]; else c[tot++] = b[j++];    while(i <= mid)c[tot++] = b[i++];    while(j <= r)c[tot++] = b[j++];    for (int i = 0; i < tot; i++) b[i+l] = c[i];}void up(int x, int p){    q[p] = x;    int t = p;    while (t > 1){        if (q[t]<q[t>>1]){int x = q[t]; q[t] = q[t>>1]; q[t>>1] = x; t = t>>1;}        else break;    }}void down(int p){    q[1] = q[p--];int t = 1, k;    while (t < p){        k = t<<1;        if (t<<1<p&&q[t<<1]>q[t<<1+1]) k = t<<1+1;        if (k <=p && q[t]>q[k]){int x = q[t]; q[t] = q[k]; q[k] = x; t = k;} else break;    }}void heap_sort(int h[], int l, int r){    for (int i = l; i <= r; i++){        up(h[i], i-l+1);    }    for (int i = l; i <= r; i++){        cout << q[1] << " ";        down(r-i+1);    }}int main(){    int num = 1;    int m;    cin >> m;    srand((unsigned)time(NULL));    while(num++ <= m){        int n = 5;        printf("第%d个测试用例:\n", num-1);        for (int i = 1; i <= n; i++){            a[i] = rand()%20;            b[i] = a[i];            h[i] = b[i];            cout << a[i] << " ";        }        cout << endl;        quick_sort(a, 1, n);        merge_sort(b, 1, n);        printf("排序结果:\n");        heap_sort(h, 1, n);cout << endl;        for (int i = 1; i <= n; i++)cout << a[i] << " "; cout << endl;        for (int i = 1; i <=n; i++) cout << b[i] << " "; cout << endl;    }    return 0;}