标签:快速排序
/*交换函数:为了提高效率,当所交换的两个元素值不相等时,用异或运算*/ void swap(int *a, int *b) { if (*a != *b){ *a = *a^*b; *b = *a^*b; *a = *a^*b; } else{ int temp = *a; *a = *b; *b = temp; } } /*第一种快排:只有一个长度n,每次需计算出low和high指针*/ int QuickSort_process1(int *a, int n) { int low, high, temp; low = 0; high = n - 1; temp = a[0]; while (low < high){ while (low < high&&temp <= a[high]) --high; if (low < high) a[low] = a[high]; while (low<high&&temp>a[low]) ++low; if (low < high) a[high] = a[low]; } a[high] = temp; return high; } void QuickSort1(int *a,int n) { int pos; if (n>0){ pos = QuickSort_process1(a, n); QuickSort1(a, pos); QuickSort1(a + pos + 1, n - pos - 1); } } /*第二种快排:有两个指针,一个快,一个慢。快的指针找比基元素小的数,慢的指针指向比基元素小的最后一个元素*/ /*这样,在排序结束后,整个数组就被基元素分为了两部分。*/ int QuickSort_process2(int *a, int n) { int first, second, temp; first = 0; second = -1; temp = a[n - 1]; while (first != n){ if (a[first] < temp){ swap(a+second+1,a+first); ++second; } ++first; } swap(a + second + 1, a + n - 1); return second + 1; } void QuickSort2(int *a, int n) { int pos; if (n > 0){ pos = QuickSort_process2(a,n); QuickSort2(a, pos); QuickSort2(a + pos + 1, n - pos - 1); } } /*第三种快排,比较传统的那种,参数中有low指针和high指针*/ int QuickSort_process3(int *a, int low, int high) { int l, h, temp; l = low; h = high; temp = a[low]; while (l < h){ while (l< h&&a[h] >= temp) --h; if (l < h) a[l] = a[h]; while (l < h&&a[l] < temp) ++l; if (l < h) a[h] = a[l]; } a[h] = temp; return h; } void QuickSort3(int *a, int low,int high) { int pos; if (low < high){ pos = QuickSort_process3(a,low,high); QuickSort3(a,low,pos-1); QuickSort3(a,pos+1,high); } }
标签:快速排序
原文地址:http://blog.csdn.net/nyist327/article/details/30115289