oj.uz

Submission #5424

# Submission time Handle Problem Language Result Execution time Memory
5424 2014-05-01T14:38:23 Z Qwaz Special graph (IZhO13_specialg) C++
40 / 100
 92 ms 22192 KB 
#include <cstdio>
#include <cmath>
#include <vector>

using namespace std;
const int MAX = 100020, BIT_MAX = 17;

int n, to[MAX], numQuery, qType[MAX], qA[MAX], qB[MAX];
vector < int > children[MAX];

void input(){
	scanf("%d", &n);

	int i;
	for(i = 1; i<=n; i++){
		scanf("%d", &to[i]);
		children[to[i]].push_back(i);
	}

	scanf("%d", &numQuery);
	for(i = 0; i<numQuery; i++){
		scanf("%d%d", &qType[i], &qA[i]);
		if(qType[i] == 2) scanf("%d", &qB[i]);
	}
}

int visited[MAX], cFull, cycleNum[MAX], cycleOrder[MAX], cycleSize[MAX];

int findCycle(int now, int visitNum){
	visited[now] = visitNum;

	if(visited[to[now]] == 0){
		int t = findCycle(to[now], visitNum);

		if(t){
			cycleNum[now] = cFull;
			cycleOrder[now] = cycleOrder[to[now]]+1;
		} else {
			cycleNum[now] = -abs(cycleNum[to[now]]);
			cycleOrder[now] = cycleOrder[to[now]];
		}

		if(now == t) return 0;
		else return t;
	} else if(visited[to[now]] == visitNum){
		cycleNum[now] = ++cFull;
		cycleOrder[now] = 1;
		return to[now];
	} else {
		cycleNum[now] = -abs(cycleNum[to[now]]);
		cycleOrder[now] = cycleOrder[to[now]];
		return 0;
	}
}

int depth[MAX], p[20][MAX];

void calcDepth(int now){
	int i;
	for(i = 0; i<children[now].size(); i++){
		int nextNum = children[now][i];
		depth[nextNum] = depth[now]+1;
		calcDepth(nextNum);
	}
}

void init(){
	int i, v = 1;
	for(i = 1; i<=n; i++){
		if(visited[i] == 0)
			findCycle(i, v++);
	}

	for(i = 1; i<=n; i++){
		if(cycleNum[i] < 0){
			if(cycleNum[to[i]] == cycleNum[i]) p[0][i] = to[i];
			else {
				p[0][i] = i;
				calcDepth(i);
			}
		} else {
			cycleSize[cycleNum[i]]++;
			p[0][i] = i;
		}
	}

	int lvl = 1;
	for(lvl = 1; lvl<=BIT_MAX; lvl++){
		for(i = 1; i<=n; i++)
			p[lvl][i] = p[lvl-1][p[lvl-1][i]];
	}
}

int uf[MAX], firstCut[MAX];
bool cycleOK[MAX];

int getParent(int num){
	if(uf[num] == num) return num;
	return uf[num] = getParent(uf[num]);
}

void link(int a, int b){
	if(getParent(a) == getParent(b)){
		cycleOK[cycleNum[a]] = 1;
	} else {
		uf[getParent(a)] = getParent(b);
	}
}

void cut(){
	int i, tNext[MAX];
	for(i = 1; i<=n; i++){
		tNext[i] = to[i];
		uf[i] = i;
	}

	for(i = 0; i<numQuery; i++){
		if(qType[i] == 1){
			if(cycleNum[qA[i]] > 0 && firstCut[cycleNum[qA[i]]] == 0)
				firstCut[cycleNum[qA[i]]] = cycleOrder[qA[i]];
			tNext[qA[i]] = 0;
		}
	}

	for(i = 1; i<=n; i++){
		if(tNext[i]){
			link(i, tNext[i]);
		}
	}
}

int cycleDist(int f, int s){
	int cn = cycleNum[f];
	if(cycleOK[cn] ||
	   (cycleOrder[f] > cycleOrder[s]
	   ? !(cycleOrder[f] >= firstCut[cn] && firstCut[cn] > cycleOrder[s])
	   : !(cycleOrder[f] >= firstCut[cn] || firstCut[cn] > cycleOrder[s]))){
		int cs = cycleSize[cn];
		return (cycleOrder[f]-cycleOrder[s]+cs) % cs;
	} else return -1;
}

int res[MAX];

void solve(){
	int i;
	for(i = numQuery-1; i>=0; i--){
		if(qType[i] == 1){
			link(qA[i], to[qA[i]]);
		} else {
			res[i] = -1;

			int f = qA[i], s = qB[i];
			if(f == s) res[i] = 0;
			else if(getParent(f) == getParent(s)){
				if(cycleNum[s] > 0){
					if(cycleNum[f] == cycleNum[s]){
						//사이클 -> 사이클
						res[i] = cycleDist(f, s);
					} else if(cycleNum[f] == -cycleNum[s]){
						//트리 -> 사이클
						int t = cycleDist(to[p[BIT_MAX][f]], s);
						if(t != -1)
							res[i] = depth[f]+1 + t;
					}
				} else {
					if(cycleNum[f] == cycleNum[s] && cycleOrder[f] == cycleOrder[s] && depth[s] < depth[f]){
						//트리 -> 트리
						int dist = depth[f]-depth[s];

						int t;
						for(t = 0; t<=BIT_MAX; t++){
							if(dist & (1<<t)){
								f = p[t][f];
							}
						}

						if(f == s)
							res[i] = dist;
					}
				}
			}
		}
	}

	for(i = 0; i<numQuery; i++){
		if(qType[i] == 2){
			printf("%d\n", res[i]);
		}
	}
}

int main(){
	input();

	init();
	cut();
	
	solve();

	return 0;
}

Subtask #1
40.0 / 100.0

# Verdict Execution time Memory Grader output
1 Incorrect 4 ms 16420 KB Output isn't correct
2 Incorrect 4 ms 16424 KB Output isn't correct
3 Incorrect 4 ms 16424 KB Output isn't correct
4 Incorrect 4 ms 16424 KB Output isn't correct
5 Incorrect 4 ms 16424 KB Output isn't correct
6 Incorrect 12 ms 16424 KB Output isn't correct
7 Incorrect 8 ms 16428 KB Output isn't correct
8 Incorrect 12 ms 16424 KB Output isn't correct
9 Correct 4 ms 16424 KB Output is correct
10 Incorrect 12 ms 16428 KB Output isn't correct
11 Correct 80 ms 22192 KB Output is correct
12 Incorrect 76 ms 18256 KB Output isn't correct
13 Correct 72 ms 19108 KB Output is correct
14 Incorrect 64 ms 18004 KB Output isn't correct
15 Correct 76 ms 18436 KB Output is correct
16 Correct 68 ms 18280 KB Output is correct
17 Correct 92 ms 19968 KB Output is correct
18 Incorrect 84 ms 19968 KB Output isn't correct
19 Correct 84 ms 19968 KB Output is correct
20 Correct 68 ms 22192 KB Output is correct