Codeforces Round #623

A. Dead Pixel

题目链接

#include 
using namespace std;
typedef long long ll;
const int inf = 0x3f3f3f3f;
const int maxn=1e9;
int a,b,x,y;
void solve()
{
	cin>>a>>b>>x>>y;
	x++,y++;
	int n,m;
	n=max(a-x,x-1);
	m=max(b-y,y-1);
	printf("%d\n",max(n*b,m*a));
}
int main()
{
 
	ll T;
    scanf("%lld\n",&T);
    while(T--)
    	solve();
    return 0;
}

B. Homecoming

题目链接

#include 
using namespace std;
typedef long long ll;
const int inf = 0x3f3f3f3f;
const int maxn=1e9;
int a,b,p;
string s;
void solve()
{
	cin>>a>>b>>p>>s;
	int len=s.size();
	int ans=len;
	int c;
	if(s[len-1-1]=='A')
		s[len-1]='B';
	else
		s[len-1]='A';
	for(int i=len-1;i>=1;i--)
	{
		if(s[i]!=s[i-1])
		{
			if(s[i-1]=='A')
				c=a;
			else
				c=b;
			if(p<c)
				break;
			else
			{
				p-=c;
				ans--;
			}
		}
		else
			ans--;
	}
	cout<<ans<<endl;
}
int main()
{

	ll T;
    scanf("%lld\n",&T);
    while(T--)
    	solve();
    return 0;
}

C. Restoring Permutation

题目链接

#include 
using namespace std;
typedef long long ll;
const int inf = 0x3f3f3f3f;
const int maxn=100+10;
int n;
int b[maxn];
int ans[2*maxn];
void solve()
{
	cin>>n;
 	map<int,int>m;
	m.clear();
	for(int i=1;i<=n;i++)
	{
		cin>>b[i];
		m[b[i]]=1;
		ans[2*i-1]=b[i];
	}
	for(int i=1;i<=n;i++)
	{
		for(int j=b[i]+1;;j++)
		{
			if(j>2*n)
			{
				puts("-1");
				return;
			}
			if(m[j]==0)
			{
				m[j]=1;
				ans[2*i]=j;
				break;
			}
		}
	}
	cout<<ans[1];
	for(int i=2;i<=2*n;i++)
		cout<<' '<<ans[i];
	cout<<endl;
	
}
int main()
{

	ll T;
    scanf("%lld\n",&T);
    while(T--)
    	solve();
    return 0;
}

D. Recommendations

题目链接
写法1：
并查集

#include 
using namespace std;
typedef long long ll;
const int inf = 0x3f3f3f3f;
const int maxn=2e5+10;
int n;
map<int,int>fa;
struct node
{
	ll num;
	int t;
}a[maxn];
bool cmp(node a,node b)
{
	return a.t==b.t?a.num<b.num:a.t>b.t;
}
int findf(int x)
{
    return fa[x]==0?x:fa[x]=findf(fa[x]);
}
void mix(int x,int y)
{
    int xx=findf(x);
    int yy=findf(y);
    if(xx!=yy)
        fa[xx]=yy;
}
void solve()
{
    cin>>n;
    for(int i=1;i<=n;i++)
        cin>>a[i].num;
    for(int i=1;i<=n;i++)
        cin>>a[i].t;
    sort(a+1,a+1+n,cmp);
    ll ans=0;
    for(int i=1;i<=n;i++)
    {
        int res=findf(a[i].num);
        if(res!=a[i].num)
            ans+=1ll*(res-a[i].num)*a[i].t;
        mix(res,res+1);
    }
    cout<<ans<<endl;
    return;
}
int main()
{
    solve();
    return 0;
}

写法2：
STL 优先队列

#include 
using namespace std;
typedef long long ll;
const int maxn=2e5+10;
struct node
{
	int num;
	int time;
}a[maxn];
int cmp(node a,node b)
{
	if(a.num==b.num)
		return a.time<b.time;
	return a.num<b.num;
}
int main()
{
	int n,i;
	cin>>n;
	for(i=1;i<=n;i++)
		cin>>a[i].num;
	for(i=1;i<=n;i++)
		cin>>a[i].time;
	sort(a+1,a+n+1,cmp);
	int now=0;
	ll sum=0,all=0;
	map<int,int>mp;
	priority_queue<int>q;
	for(i=1;i<=n;i++)
	{
		if(a[i].num==a[i-1].num)
		{
			if(a[i].time<mp[a[i].num])
			{
				q.push(a[i].time);
				sum+=a[i].time;
			}
			else
			{
				q.push(mp[a[i].num]);
				sum+=mp[a[i].num];
				mp[a[i].num]=a[i].time;
			}
			now=a[i].num;
		}
		else
		{
			while(now<a[i].num)
			{
				if(sum==0)
					break;
				all+=sum;
				now++;
				if(now<a[i].num)
				{
					sum-=q.top();
					q.pop();
				}
			}
			if(!q.empty())
			{
				if(a[i].time<q.top())
				{
					sum-=q.top();
					sum+=a[i].time;
					mp[a[i].num]=q.top();
					q.pop();
					q.push(a[i].time);
				}
				else
					mp[a[i].num]=a[i].time;
			}
			else
				mp[a[i].num]=a[i].time;
		}
	}
	while(!q.empty())
	{
		all+=sum;
		sum-=q.top();
		q.pop();
	}
	cout<<all<<endl;
}