Submission #341266

#	Time	Username	Problem	Language	Result	Execution time	Memory
341266		juggernaut	Marriage questions (IZhO14_marriage)	C++14	100 / 100	440 ms	3504 KiB

marriage

#include "bits/stdc++.h"
#define MAXN 100009
#define INF 1000000007
#define mp(x,y) make_pair(x,y)
#define all(v) v.begin(),v.end()
#define pb(x) push_back(x)
#define wr cout<<"----------------"<<endl;
#define ppb() pop_back()
#define tr(ii,c) for(__typeof((c).begin()) ii=(c).begin();ii!=(c).end();ii++)
#define ff first
#define ss second
#define my_little_dodge 46
#define debug(x)  cerr<< #x <<" = "<< x<<endl;
using namespace std;
 
typedef long long ll;
typedef pair<int,int> PII;
template<class T>bool umin(T& a,T b){if(a>b){a=b;return 1;}return 0;}
template<class T>bool umax(T& a,T b){if(a<b){a=b;return 1;}return 0;}
int vis[MAXN],l,r=1,ver;
vector<int>adj[MAXN];
int match[MAXN];
bool dfs(int nd){
	if(vis[nd]==ver)return 0;
	vis[nd]=ver;
	tr(it,adj[nd])
		if(l<=*it and *it<=r)
			if(match[*it]==-1 or dfs(match[*it])){
				match[*it]=nd;
				return 1;	
			}	
	return 0;
}
int main(){
    //freopen("file.in", "r", stdin);
    int n,m,k;
    scanf("%d%d%d",&n,&m,&k);
    for(int i=1;i<=k;i++){
    	int a,b;
		scanf("%d%d",&a,&b);
		adj[b].pb(a);	
    }
    for(int i=1;i<=m;i++)sort(all(adj[i]));
    vector<int>need;
    for(int i=1;i<=m;i++)
    	need.pb(i);
    for(int i=1;i<=n;i++)
    	match[i]=-1;
    ll ans=0;
    for(l=1;max(r,l)<=n;l++){
    	while(!need.empty()){
			int nd=need.back();ver++;
			while(r<=n and !dfs(nd))
				r++,ver++;
			if(r>n)
				break;
			need.ppb();
		}
		ans+=n-r+1;
		if(~match[l])
			need.pb(match[l]),match[l]=-1;
    }
    printf("%lld\n",ans);
	return 0;
}

Compilation message (stderr)

marriage.cpp: In function 'int main()':
marriage.cpp:37:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   37 |     scanf("%d%d%d",&n,&m,&k);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~
marriage.cpp:40:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   40 |   scanf("%d%d",&a,&b);
      |   ~~~~~^~~~~~~~~~~~~~

• Subtask 1: 100 / 100