UV 11525, uva11525

UV 11525, uva11525
Ultraviolet A 11525-Permutation

Question Link

Given a k number, the nth number is arranged in full order. Because n is large, the input method is Σ.K1SIPartition (K−I)!

Idea: In full arrangement, it is easy to see that the si corresponds to the number k in the array, so the problem is to find the number k at a time, and then remove the number, the tree array is easy to implement.

Code:

#include <cstdio>#include <cstring>#define lowbit(x) (x&(-x))const int N = 50005;int t, k, bit[N];void add(int x, int v) {    while (x <= k) {bit[x] += v;x += lowbit(x);    }}int get(int x) {    int ans = 0, num = 0;    for (int i = 16; i >= 0; i--) {ans += (1<<i);if (ans >= k || bit[ans] + num >= x)    ans -= (1<<i);else num += bit[ans];    }    return ans + 1;}int main() {    scanf("%d", &t);    while (t--) {memset(bit, 0, sizeof(bit));scanf("%d", &k);for (int i = 1; i <= k; i++)    add(i, 1);int num;for (int i = 1; i <= k; i++) {    scanf("%d", &num);    num++;    int v = get(num);    printf("%d%c", v, i == k ? '\n' : ' ');    add(v, -1);}    }    return 0;}