merge-sort.cpp

#include <stdio.h>
int temp[100002], a[100002] = {9, 8, 1, 3, 7, 2, 6, 4, 0, 5};

void merge(int start, int end) {
	int min = (start + end) / 2, i = 0, j = 0;
	int fi = start, bi = min, len = end - start;
	if (min - start > 1)
		merge(start, min);
	if (end - min > 1)
		merge(min, end);
	while (fi < min && bi < end && i < len) {
		if (a[fi] > a[bi]) {
			temp[i] = a[bi];
			bi++;
		} else {
			temp[i] = a[fi];
			fi++;
		}
		i++;
	}
	while (fi < min) {
		temp[i] = a[fi];
		fi++;
		i++;
	}
	while (j < i) {
		a[start + j] = temp[j];
		j++;
	}
}

main() {
	int n = 10;
	merge(0, n);
	for (int i = 0; i < n; i++)
		printf("%d ", a[i]);
}