oj.uz

Submission #5430

# Submission time Handle Problem Language Result Execution time Memory
5430 2014-05-01T22:53:58 Z Qwaz Special graph (IZhO13_specialg) C++
40 / 100
 88 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 != -1){
			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 -1;
		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 -1;
	}
}

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){
			int cn = cycleNum[qA[i]];
			if(cn > 0 && firstCut[cn] == 0){
				firstCut[cn] = 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(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 16420 KB Output isn't correct
3 Incorrect 0 ms 16424 KB Output isn't correct
4 Incorrect 4 ms 16424 KB Output isn't correct
5 Incorrect 0 ms 16416 KB Output isn't correct
6 Incorrect 12 ms 16420 KB Output isn't correct
7 Incorrect 8 ms 16424 KB Output isn't correct
8 Incorrect 12 ms 16424 KB Output isn't correct
9 Correct 12 ms 16424 KB Output is correct
10 Incorrect 8 ms 16428 KB Output isn't correct
11 Correct 72 ms 22192 KB Output is correct
12 Incorrect 68 ms 18260 KB Output isn't correct
13 Correct 80 ms 19104 KB Output is correct
14 Incorrect 72 ms 18008 KB Output isn't correct
15 Correct 72 ms 18440 KB Output is correct
16 Correct 80 ms 18280 KB Output is correct
17 Correct 88 ms 19968 KB Output is correct
18 Incorrect 84 ms 19972 KB Output isn't correct
19 Correct 84 ms 19968 KB Output is correct
20 Correct 64 ms 22192 KB Output is correct