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merge pass.cpp
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merge pass.cpp
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#include <stdio.h>
#include<stdlib.h>
#define ElementType int
#define MAXN 100
void merge_pass(ElementType list[], ElementType sorted[], int N, int length);
void output(ElementType list[], int N)
{
int i;
for (i = 0; i<N; i++) printf("%d ", list[i]);
printf("\n");
}
void merge_sort(ElementType list[], int N)
{
ElementType extra[MAXN]; /* the extra space required */
int length = 1; /* current length of sublist being merged */
while (length < N) {
merge_pass(list, extra, N, length); /* merge list into extra */
output(extra, N);
length *= 2;
merge_pass(extra, list, N, length); /* merge extra back to list */
output(list, N);
length *= 2;
}
}
int main()
{
int N, i;
ElementType A[MAXN];
scanf("%d", &N);
for (i = 0; i<N; i++) scanf("%d", &A[i]);
merge_sort(A, N);
output(A, N);
system("pause");
return 0;
}
/*
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8 7 9 2 3 5 1 6 4 0
*/
void merge_pass(ElementType list[], ElementType sorted[], int N, int length)
{
int left = 0;
int right = (left + length) > N ? N : (left + length);
int top = 0;
while (left < right)
{
int cl = left;
int cr = right;
while (left < cl + length&&left < N&&right < cr + length&&right < N)
{
if (list[left]<list[right])
{
sorted[top++] = list[left++];
}
else
{
sorted[top++] = list[right++];
}
}
while (left < cl + length&&left < N)
sorted[top++] = list[left++];
while (right < cr + length&&right < N)
sorted[top++] = list[right++];
left = (cl + 2 * length) < N ? (cl + 2 * length) : N;
right = (cr + 2 * length) < N ? (cr + 2 * length) : N;
}
}