Submission #1227426

#	Time	Username	Problem	Language	Result	Execution time	Memory
1227426		chaeryeong	Rope (JOI17_rope)	C++20	0 / 100	12 ms	23872 KiB

rope

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = 1e6 + 1;
int n, m, c[N], mn[N];
vector <int> occ[N];
void solve () {
	cin >> n >> m;
	for (int i = 1; i <= n; i++) {
		cin >> c[i];
		occ[c[i]].push_back(i);
	}
	for (int i = 1; i <= m; i++) {
		mn[i] = 1e9;
	}
	if (n % 2 == 1) {
		vector <int> ff(m + 1, 0);
		for (int i = 1; i <= n; i++) {
			ff[c[i]]++;
		}
		set <pair <int, int>> mxs;
		for (int i = 1; i <= m; i++) {
			mxs.insert({ff[i], i});
		}
		for (int i = 1; i <= m; i++) {
			mxs.erase({ff[i], i});
			int s = n, v = 0;
			for (auto j : occ[i]) {
				if (j % 2 == 1) {
					if (j + 1 <= n) {
						if (c[j + 1] != i) {
							v++;
							mxs.erase({ff[c[j + 1]], c[j + 1]});
							ff[c[j + 1]]--;
							mxs.insert({ff[c[j + 1]], c[j + 1]});
						}
					}
					if (j == n) {
						s--;
					} else {
						s -= 2;
					}
				} else {
					if (c[j - 1] != i) {
						v++;
						mxs.erase({ff[c[j - 1]], c[j - 1]});
						ff[c[j - 1]]--;
						mxs.insert({ff[c[j - 1]], c[j - 1]});
						s -= 2;
					}
				}
			}
			mn[i] = min(mn[i], v + s - (mxs.empty() ? 0 : (*(--mxs.end())).first));
			for (auto j : occ[i]) {
				if (j % 2 == 1) {
					if (j + 1 <= n) {
						if (c[j + 1] != i) {
							mxs.erase({ff[c[j + 1]], c[j + 1]});
							ff[c[j + 1]]++;
							mxs.insert({ff[c[j + 1]], c[j + 1]});
						}
					}
				} else {
					if (c[j - 1] != i) {
						mxs.erase({ff[c[j - 1]], c[j - 1]});
						ff[c[j - 1]]++;
						mxs.insert({ff[c[j - 1]], c[j - 1]});
					}
				}
			}
			mxs.insert({ff[i], i});
		}
	}
	if (n % 2 == 1) {
		for (int i = 1; i <= m; i++) {
			vector <int> ff(m + 1, 0);
			int s = 0, v = 0;
			for (int j = 2; j <= n; j += 2) {
				if (c[j] != i && c[j + 1] != i) {
					ff[c[j]]++;
					ff[c[j + 1]]++;
					s += 2;
				} else {
					v += c[j] != i;
					v += c[j + 1] != i;
				}
			}
			if (c[1] != i) {
				ff[c[1]]++;
				s++;
			} 
			mn[i] = min(mn[i], v + s - *max_element(ff.begin(), ff.end()));
		}
	}
	if (n % 2 == 0) {
		for (int i = 1; i <= m; i++) {
			vector <int> ff(m + 1, 0);
			int s = 0, v = 0;
			for (int j = 2; j < n; j += 2) {
				if (c[j] != i && c[j + 1] != i) {
					ff[c[j]]++;
					ff[c[j + 1]]++;
					s += 2;
				} else {
					v += c[j] != i;
					v += c[j + 1] != i;
				}
			}
			if (c[1] != i) {
				ff[c[1]]++;
				s++;
			} 
			if (c[n] != i) {
				ff[c[n]]++;
				s++;
			} 
			mn[i] = min(mn[i], v + s - *max_element(ff.begin(), ff.end()));
		}
	}
	if (n % 2 == 0) {
		for (int i = 1; i <= m; i++) {
			vector <int> ff(m + 1, 0);
			int s = 0, v = 0;
			for (int j = 1; j <= n; j += 2) {
				if (c[j] != i && c[j + 1] != i) {
					ff[c[j]]++;
					ff[c[j + 1]]++;
					s += 2;
				} else {
					v += c[j] != i;
					v += c[j + 1] != i;
				}
			}
			mn[i] = min(mn[i], v + s - *max_element(ff.begin(), ff.end()));
		}
	}	
	for (int i = 1; i <= m; i++) {
		cout << mn[i] << '\n';
	}
}
signed main () {
	#ifndef ONLINE_JUDGE 
		freopen("input_file", "r", stdin);
		freopen("output_file", "w", stdout);
	#endif
	ios::sync_with_stdio(0); cin.tie(0);
	int tc = 1; //cin >> tc;
	while (tc--) solve();
}

Compilation message (stderr)

rope.cpp: In function 'int main()':
rope.cpp:143:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  143 |                 freopen("input_file", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
rope.cpp:144:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  144 |                 freopen("output_file", "w", stdout);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 15
• Subtask 2: 0 / 30
• Subtask 3: 0 / 10
• Subtask 4: 0 / 25
• Subtask 5: 0 / 20