排序算法模板（C语言版）

1.快速排序

//By LYLtim



void swap(int *a, int *b)

{

	int t = *a;

	*a = *b;

	*b = t; 

}



void QSort(int l, int r)

{

	int lp = l, rp = r, m = (l + r) >> 1;

	while (lp < rp) {

		while (a[lp] < a[m]) lp++;

		while (a[rp] > a[m]) rp--;

		if (lp <= rp)

			swap(&a[lp++], &a[rp--]);

	}

	if (l < rp) QSort(l, rp);

	if (lp < r) QSort(lp, r);

}

 C语音标准库函数qsort用法

1 int cmp(const void *a,const void *b) {

2     return ( *(int*)a - *(int*)b );

3 }

4 qsort(a, n, sizeof(int), cmp);

详见：http://www.cplusplus.com/reference/cstdlib/qsort

 

2.归并排序

//By LYLtim



void merge(int start, int mid, int end)

{

	int	pl, pr, p = start,

		len1 = mid - start + 1,

		len2 = end - mid,

		left[len1], right[len2];

	for (pl = 0; pl < len1; pl++) left[pl] = a[start+pl];

	for (pr = 0; pr < len2; pr++) right[pr] = a[mid+1+pr];

	pl = pr = 0;

	while (pl < len1 && pr < len2)

		if (left[pl] < right[pr]) a[p++] = left[pl++];

		else a[p++] = right[pr++];

	while (pl < len1) a[p++] = left[pl++];

	while (pr < len2) a[p++] = right[pr++];

}

			

void sort(int start, int end)

{

	if (start < end) {

		int mid = (start + end) >> 1;

		sort(start, mid);

		sort(mid+1, end);

		merge(start, mid, end);

	}

}

 

3.希尔排序

//By LYLtim

void ShellSort(int a[], unsigned n)

{

	unsigned gap, i, j;

	for (gap = n >> 1; gap > 0; gap >>= 1)

		for (i = gap; i < n; i++)

			for (j = i - gap; j >= 0 && a[j] > a[j + gap]; j -= gap)

				swap(&a[j], &a[j + gap]);

}