Submission #356755

#	Time	Username	Problem	Language	Result	Execution time	Memory
356755		LucaDantas	Skandi (COCI20_skandi)	C++17	110 / 110	181 ms	15476 KiB

Main

#include<bits/stdc++.h>
using namespace std;
 
using pii = pair<int,int>;
 
#define pb push_back
 
constexpr int maxn = 3e5+10, inf = 0x3f3f3f3f;
 
int color[maxn], match[maxn], dist[maxn];
bool mark[maxn];
 
vector<int> g[maxn];

bool bfs(int n) {
	queue<int> q;
	for(int i = 1; i <= n; i++) {
		if(match[i] == 0) {
			dist[i] = 0;
			q.push(i);
		}
		else dist[i] = inf;
	}
	dist[0] = inf;
	while(!q.empty()) {
		int v = q.front(); q.pop();
		for(int u : g[v]) {
			if(dist[match[u]] == inf) {
				dist[match[u]] = dist[v] + 1;
				q.push(match[u]);
			}
		}
	}
	return (dist[0] != inf);
}

bool dfs(int v){
	if(!v) return 1;
	for(int u : g[v]) {
		if(dist[match[u]] == dist[v] + 1 && dfs(match[u])) {
			match[u] = v;
			match[v] = u;
			return 1;
		}
	}
	dist[v] = inf;
	return 0;
}

int hopcroftKarp(int n) {
	for(int i = 1; i <=n; i++) match[i]=0;
	int matching = 0;
	while(bfs(n)) for(int i = 1; i <=n; i++) if(!match[i] && dfs(i)) matching++;
	return matching;
}

bool in[maxn];
 
vector<int> t;
 
void dfs2(int u) {
	mark[u] = 1;
 
	if(color[u]) return (void)(t.pb(u), dfs2(match[u]));
 
	in[u] = 1;
	for(int v : g[u]) {
		if(mark[v]) continue;
		dfs2(v);
	}
}
 
pii sv[maxn];
 
int main() {
	int n, m; scanf("%d %d", &n, &m);
	
	vector<int> last_ptr(m), ultimo_c(m);
	ultimo_c[0] = 1;
	int atras = 0, now = 0, ptr = 1;
	
	for(int k = 0; k < n; k++) {
		for(int i = 0; i < m; i++) {
			char c; scanf(" %c", &c);
			int a = c-'0';
			if(a && !atras) now = ptr++;
			if(a && !ultimo_c[i]) ++color[ptr], last_ptr[i] = ptr++;
			else if(!a) {
				g[now].pb(last_ptr[i]), g[last_ptr[i]].pb(now);
				if(sv[now] == make_pair(0, 0))
					sv[now] = {k, i-1};
				if(sv[last_ptr[i]] == make_pair(0, 0))
					sv[last_ptr[i]] = {k-1, i};
			}
			atras = a;
			ultimo_c[i] = a;
		}
	}
 
	memset(mark, 0, sizeof mark);
	printf("%d\n", hopcroftKarp(ptr-1));
 
	for(int i = 1; i < ptr; i++) {
		if(color[i] || match[i] || mark[i]) continue;
		dfs2(i);
	}
 
	for(int i = 1; i < ptr; i++)
		if(!in[i] && !color[i]) printf("%d %d DESNO\n", sv[i].first+1, sv[i].second+1);
	for(int x : t)
		printf("%d %d DOLJE\n", sv[x].first+1, sv[x].second+1);	
}

Compilation message (stderr)

skandi.cpp: In function 'int main()':
skandi.cpp:76:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   76 |  int n, m; scanf("%d %d", &n, &m);
      |            ~~~~~^~~~~~~~~~~~~~~~~
skandi.cpp:84:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   84 |    char c; scanf(" %c", &c);
      |            ~~~~~^~~~~~~~~~~

• Subtask 1: 18 / 18
• Subtask 2: 32 / 32
• Subtask 3: 60 / 60