不使用递归实现归并排序

《数据结构与算法分析——c语言描述》  练习7.14 答案

直接从相邻2个，4个，8个……排序，要注意的最后的结尾如何处理

#include<stdlib.h>
#include<stdio.h>
#include"fatal.h"
int RandInt(int i, int j) {
int temp;
temp = (int)(i + (1.0*rand() / RAND_MAX)*(j - i));
return temp;
}

void getRandomInt(int *A, int n) {
for (int i = 0; i < n; i++) {
A[i] = i + 1;
}

for (int i = 1; i < n; i++) {
//std::swap(A[i], A[RandInt(0, i)]);
int randAdrr = RandInt(0, i);
int t = A[i];
A[i] = A[randAdrr];
A[randAdrr] = t;
}
}

int a[99999999];

void merge(int a[], int tempArray[], int left, int right, int rightEnd) {
int i, j, k;
int leftEnd;
for (i = left, j = right, k = left, leftEnd = right - 1; i <= leftEnd && j <= rightEnd; k++) {
if (a[i] < a[j]) {
tempArray[k] = a[i];
i++;
}
else {
tempArray[k] = a[j];
j++;
}
}
while (i <= leftEnd) {
tempArray[k++] = a[i++];
}
while (j <= rightEnd) {
tempArray[k++] = a[j++];
}
for (int i = left; i <= rightEnd; i++)
a[i] = tempArray[i];
}

void mSort(int a[], int tempArray[], int left, int right) {
if (left < right) {
int center = (left + right) / 2;
mSort(a, tempArray, left, center);
mSort(a, tempArray, center + 1, right);
merge(a, tempArray, left, center + 1, right);
}
}

void mergeSort(int a[], int n) {
int *tempArray = malloc(sizeof(int)*n);
if (tempArray == NULL)
Error("OUT OF MEMORY");
//mSort(a, tempArray, 0, n - 1);
for (int len = 1; len < n; len *= 2) {

for (int beg_pos = 0; beg_pos < n; beg_pos += (2 * len)) {
{
int i, j, k;
int leftEnd, rightEnd;
for (i = beg_pos, j = beg_pos + len, k = beg_pos, leftEnd = min(j - 1, n - 1), rightEnd = min(j + len - 1, n - 1); i <= leftEnd && j <= rightEnd; k++) {
if (a[i] < a[j]) {
tempArray[k] = a[i];

i++;
}
else {
tempArray[k] = a[j];

j++;
}

}
while (i <= leftEnd) {
tempArray[k++] = a[i++];

}
while (j <= rightEnd) {
tempArray[k++] = a[j++];

}
for (int i = beg_pos; i <= rightEnd; i++)
a[i] = tempArray[i];
}
}

}
free(tempArray);
}

#define N 2222

int main() {
getRandomInt(a, N);
mergeSort(a, N);
int cnt = 1;
for (int i = 0; i < N; i++)
if (cnt == a[i])
cnt++;
else
Error("error");

}