AcWing 787. 归并排序
#include <iostream> using namespace std; const int N = 1e6 + 10; int n; int q[N], tmp[N]; void merge_sort(int q[], int l, int r) { if (l >= r) return ; int mid = l + r >> 1; merge_sort(q, l, mid); merge_sort(q, mid + 1, r); int i = l, j = mid + 1, k = 0; while (i <= mid && j <= r) { if (q[i] < q[j]) tmp[k ++] = q[i ++]; else tmp[k ++] = q[j ++]; } while (i <= mid) tmp[k ++] = q[i ++]; while (j <= r) tmp[k ++] = q[j ++]; for (int i = l, j = 0; i <= r; ++ i, ++ j) q[i] = tmp[j]; return ; } int main() { cin >> n; for (int i = 0; i < n; ++ i) cin >> q[i]; merge_sort(q, 0, n - 1); for (int i = 0; i < n; ++ i) cout << q[i] << " "; return 0; }