Submission #136437

# Submission time Handle Problem Language Result Execution time Memory
136437 2019-07-25T10:07:27 Z onjo0127 Link (CEOI06_link) C++11
92 / 100
577 ms 51872 KB
#include <bits/stdc++.h>
using namespace std;
#define sz(V) ((int)V.size())

const int _N = 500001, DBG = 0;
bool chk[_N];
int N, K, A[_N], vs[_N], dep[_N], rt[_N], rid[_N], ith[_N], p[_N], cs[_N], ans;
vector<vector<int> > R;
vector<int> S, G[_N];

void go(int x, int col) {
	S.push_back(x);
	vs[x] = col;
	if(vs[A[x]]) {
		if(vs[A[x]] == col) {
			vector<int> T;
			while(1) {
				int tmp = S.back(); S.pop_back();
				T.push_back(tmp);
				if(tmp == A[x]) break;
			}
			reverse(T.begin(), T.end());
			for(int i=0; i<T.size(); i++) rid[T[i]] = sz(R), ith[T[i]] = i+1;
			R.push_back(T);
		}
	}
	else go(A[x], col);
}

int mrk(int x, int k) {
	if(k <= 0) return x;
	chk[x] = 1;
	int d;
	if(ith[x]) {
		if(ith[x] < ith[A[x]]) d = ith[A[x]] - ith[x];
		else d = ith[A[x]] - ith[x] + sz(R[rid[x]]);
	}
	else if(ith[A[x]]) return A[x] = mrk(rt[x], k - dep[x]);
	else d = dep[x] - dep[A[x]];
	return A[x] = mrk(A[x], k - d);
}

void dfs(int RT, int x, int d) {
	// printf("dfs: x: %d, d: %d\n", x, d);
	dep[x] = d; rt[x] = RT;
	for(auto& it: G[x]) dfs(RT, it, d+1);
}

void showstat() {
	puts("Showing...");
	printf("answer: %d\n", ans);
	for(int i=1; i<=N; i++) printf("%d", chk[i]);
	puts("\n---------------------");
}

int main() {
	vector<int> Q;
	scanf("%d%d",&N,&K);
	for(int i=1; i<=N; i++) {
		int a, b; scanf("%d%d",&a,&b);
		A[a] = b;
	}
	for(int i=1; i<=N; i++) if(!vs[i]) go(i, i);
	for(int i=1; i<=N; i++) if(!ith[i]) {
		G[A[i]].push_back(i);
		Q.push_back(i);
	}
	for(int i=1; i<=N; i++) if(ith[i]) dfs(i, i, 0);
	chk[1] = 1;
	mrk(A[1], K);
	if(DBG) showstat();
	sort(Q.begin(), Q.end(), [&](int PP, int QQ) { return dep[PP] > dep[QQ]; });
	for(auto& it: Q) {
		if(chk[it]) continue;
		mrk(it, K); ++ans;
	}
	if(DBG) showstat();

	set<int> st;
	for(auto& it: R) {
		st.clear();
		int M = sz(it);
		for(int j=0; j<M; j++) {
			p[j] = j; cs[j] = 0;
			if(!chk[it[j]]) st.insert(j);
		}
		if(st.empty()) continue;

		for(auto& jt: st) {
			if(jt <= M-K) {
				auto kt = st.lower_bound(jt + K);
				if(kt == st.end()) {
					p[jt] = *st.begin();
					cs[jt] = *st.begin() - jt + M;
				}
				else {
					p[jt] = *kt;
					cs[jt] = *kt - jt;
				}
			}
			else {
				auto kt = st.lower_bound(jt + K - M);
				if(kt == st.end()) p[jt] = jt, cs[jt] = M;
				else p[jt] = *kt, cs[jt] = *kt - jt + M;
			}
			// printf("next[%d]: %d, cost: %d\n", jt, p[0][jt], cs[0][jt]);
		}

		st.insert(1e9);

		int mn = 1e9, stt = *st.begin();
		for(int j=stt; j<stt+K; j++) {
			int jt = j % M;
			if(*st.lower_bound(jt) != jt) continue;
			int sum = 0, cnt = 0, now = jt;
			while(sum < M) {
				sum += cs[now];
				++cnt;
				now = p[now];
			}
			mn = min(mn, cnt);
		}
		ans += mn;
	}
	printf("%d", ans);
	return 0;
}

Compilation message

link.cpp: In function 'void go(int, int)':
link.cpp:23:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for(int i=0; i<T.size(); i++) rid[T[i]] = sz(R), ith[T[i]] = i+1;
                 ~^~~~~~~~~
link.cpp: In function 'int main()':
link.cpp:58:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&N,&K);
  ~~~~~^~~~~~~~~~~~~~
link.cpp:60:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   int a, b; scanf("%d%d",&a,&b);
             ~~~~~^~~~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 12 ms 12152 KB Output is correct
2 Incorrect 12 ms 12152 KB Output isn't correct
3 Correct 13 ms 12152 KB Output is correct
4 Correct 14 ms 12280 KB Output is correct
5 Incorrect 14 ms 12408 KB Output isn't correct
6 Correct 30 ms 14456 KB Output is correct
7 Correct 43 ms 15348 KB Output is correct
8 Correct 58 ms 17140 KB Output is correct
9 Correct 89 ms 21476 KB Output is correct
10 Correct 83 ms 20888 KB Output is correct
11 Correct 154 ms 36976 KB Output is correct
12 Correct 218 ms 23400 KB Output is correct
13 Correct 234 ms 31828 KB Output is correct
14 Correct 291 ms 36264 KB Output is correct
15 Correct 325 ms 38828 KB Output is correct
16 Correct 384 ms 48344 KB Output is correct
17 Correct 432 ms 43588 KB Output is correct
18 Correct 514 ms 46012 KB Output is correct
19 Correct 490 ms 45744 KB Output is correct
20 Correct 474 ms 43736 KB Output is correct
21 Correct 566 ms 47212 KB Output is correct
22 Correct 513 ms 49104 KB Output is correct
23 Correct 555 ms 51872 KB Output is correct
24 Correct 505 ms 49076 KB Output is correct
25 Correct 577 ms 48228 KB Output is correct