「比賽總結」AT ABC 358 總結

wangmarui發表於2024-06-16

還行,\(6\) 題。

切題順序是 ABCDGE。

下面講下過的題的思路吧。

A

直接判斷即可。

點選檢視程式碼
/*
Tips:
你陣列開小了嗎?
你MLE了嗎?
你覺得是貪心,是不是該想想dp?
一個小時沒調出來,是不是該考慮換題?
打 cf 不要用 umap!!!

記住,rating 是身外之物。

該衝正解時衝正解!

Problem:

演算法:

思路:

*/
#include<bits/stdc++.h>
using namespace std;
//#define map unordered_map
#define forl(i,a,b) for(register long long i=a;i<=b;i++)
#define forr(i,a,b) for(register long long i=a;i>=b;i--)
#define forll(i,a,b,c) for(register long long i=a;i<=b;i+=c)
#define forrr(i,a,b,c) for(register long long i=a;i>=b;i-=c)
#define lc(x) x<<1
#define rc(x) x<<1|1
#define mid ((l+r)>>1)
#define cin(x) scanf("%lld",&x)
#define cout(x) printf("%lld",x)
#define lowbit(x) (x&-x)
#define pb push_back
#define pf push_front
#define IOS ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);
#define endl '\n'
#define QwQ return 0;
#define ll long long
#define ull unsigned long long
#define lcm(x,y) x/__gcd(x,y)*y
#define Sum(x,y) 1ll*(x+y)*(y-x+1)/2
#define aty cout<<"Yes\n";
#define atn cout<<"No\n";
#define cfy cout<<"YES\n";
#define cfn cout<<"NO\n";
#define xxy cout<<"yes\n";
#define xxn cout<<"no\n";
#define printcf(x) x?cout<<"YES\n":cout<<"NO\n";
#define printat(x) x?cout<<"Yes\n":cout<<"No\n";
#define printxx(x) x?cout<<"yes\n":cout<<"no\n";
ll t;
string s1,s2;
void solve()
{
	cin>>s1>>s2;
	printat(s1=="AtCoder" && s2=="Land");
}
int main()
{
	IOS;
	t=1;
 //	cin>>t;
	while(t--)
		solve();
    /******************/
	/*while(L<q[i].l) */
	/*    del(a[L++]);*/
	/*while(L>q[i].l) */
	/*    add(a[--L]);*/
	/*while(R<q[i].r) */
	/*	  add(a[++R]);*/
	/*while(R>q[i].r) */
	/*    del(a[R--]);*/
    /******************/
	QwQ;
}

B

直接模擬即可。

點選檢視程式碼
/*
Tips:
你陣列開小了嗎?
你MLE了嗎?
你覺得是貪心,是不是該想想dp?
一個小時沒調出來,是不是該考慮換題?
打 cf 不要用 umap!!!

記住,rating 是身外之物。

該衝正解時衝正解!

Problem:

演算法:

思路:

*/
#include<bits/stdc++.h>
using namespace std;
//#define map unordered_map
#define forl(i,a,b) for(register long long i=a;i<=b;i++)
#define forr(i,a,b) for(register long long i=a;i>=b;i--)
#define forll(i,a,b,c) for(register long long i=a;i<=b;i+=c)
#define forrr(i,a,b,c) for(register long long i=a;i>=b;i-=c)
#define lc(x) x<<1
#define rc(x) x<<1|1
#define mid ((l+r)>>1)
#define cin(x) scanf("%lld",&x)
#define cout(x) printf("%lld",x)
#define lowbit(x) (x&-x)
#define pb push_back
#define pf push_front
#define IOS ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);
#define endl '\n'
#define QwQ return 0;
#define ll long long
#define ull unsigned long long
#define lcm(x,y) x/__gcd(x,y)*y
#define Sum(x,y) 1ll*(x+y)*(y-x+1)/2
#define aty cout<<"Yes\n";
#define atn cout<<"No\n";
#define cfy cout<<"YES\n";
#define cfn cout<<"NO\n";
#define xxy cout<<"yes\n";
#define xxn cout<<"no\n";
#define printcf(x) x?cout<<"YES\n":cout<<"NO\n";
#define printat(x) x?cout<<"Yes\n":cout<<"No\n";
#define printxx(x) x?cout<<"yes\n":cout<<"no\n";
ll t;
ll n,m;
ll a[100010],ans;
void solve()
{
	cin>>n>>m;
	forl(i,1,n)
	{
		cin>>a[i];
		ans=max(a[i]+m,ans+m);
		cout<<ans<<endl;
	}
}
int main()
{
	IOS;
	t=1;
 //	cin>>t;
	while(t--)
		solve();
    /******************/
	/*while(L<q[i].l) */
	/*    del(a[L++]);*/
	/*while(L>q[i].l) */
	/*    add(a[--L]);*/
	/*while(R<q[i].r) */
	/*	  add(a[++R]);*/
	/*while(R>q[i].r) */
	/*    del(a[R--]);*/
    /******************/
	QwQ;
}

C

解法一

dfs,\(O(2^n \times m)\)

解法二

狀壓,\(O(2^n \times n)\)

這裡我寫的狀壓。

點選檢視程式碼
/*
Tips:
你陣列開小了嗎?
你MLE了嗎?
你覺得是貪心,是不是該想想dp?
一個小時沒調出來,是不是該考慮換題?
打 cf 不要用 umap!!!

記住,rating 是身外之物。

該衝正解時衝正解!

Problem:

演算法:

思路:

*/
#include<bits/stdc++.h>
using namespace std;
//#define map unordered_map
#define forl(i,a,b) for(register long long i=a;i<=b;i++)
#define forr(i,a,b) for(register long long i=a;i>=b;i--)
#define forll(i,a,b,c) for(register long long i=a;i<=b;i+=c)
#define forrr(i,a,b,c) for(register long long i=a;i>=b;i-=c)
#define lc(x) x<<1
#define rc(x) x<<1|1
#define mid ((l+r)>>1)
#define cin(x) scanf("%lld",&x)
#define cout(x) printf("%lld",x)
#define lowbit(x) (x&-x)
#define pb push_back
#define pf push_front
#define IOS ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);
#define endl '\n'
#define QwQ return 0;
#define ll long long
#define ull unsigned long long
#define lcm(x,y) x/__gcd(x,y)*y
#define Sum(x,y) 1ll*(x+y)*(y-x+1)/2
#define aty cout<<"Yes\n";
#define atn cout<<"No\n";
#define cfy cout<<"YES\n";
#define cfn cout<<"NO\n";
#define xxy cout<<"yes\n";
#define xxn cout<<"no\n";
#define printcf(x) x?cout<<"YES\n":cout<<"NO\n";
#define printat(x) x?cout<<"Yes\n":cout<<"No\n";
#define printxx(x) x?cout<<"yes\n":cout<<"no\n";
ll t;
ll n;
ll m;
char a[20][20];
ll num[20];
ll pw(ll x){
	return 1ll<<x;
}
ll f(ll x)
{
	ll s=0;
	while(x)
		s+=x%2,x/=2;
	return s; 
}
void solve()
{
	ll ans=1e18;
	cin>>n>>m;
	forl(i,1,n)
		forl(j,1,m)
			cin>>a[i][j],num[i]|=(a[i][j]=='o')*pw(j-1);
	forl(i,0,pw(n)-1)
	{
		ll sum=0;
		forl(j,0,n-1)
			if(i&pw(j))
				sum|=num[j+1];
		if(sum==pw(m)-1)
			ans=min(ans,f(i));
	}
	cout<<ans<<endl;
}
int main()
{
	IOS;
	t=1;
 //	cin>>t;
	while(t--)
		solve();
    /******************/
	/*while(L<q[i].l) */
	/*    del(a[L++]);*/
	/*while(L>q[i].l) */
	/*    add(a[--L]);*/
	/*while(R<q[i].r) */
	/*	  add(a[++R]);*/
	/*while(R>q[i].r) */
	/*    del(a[R--]);*/
    /******************/
	QwQ;
}

D

雙指標,貪心顯然。

點選檢視程式碼
/*
Tips:
你陣列開小了嗎?
你MLE了嗎?
你覺得是貪心,是不是該想想dp?
一個小時沒調出來,是不是該考慮換題?
打 cf 不要用 umap!!!

記住,rating 是身外之物。

該衝正解時衝正解!

Problem:

演算法:

思路:

*/
#include<bits/stdc++.h>
using namespace std;
//#define map unordered_map
#define forl(i,a,b) for(register long long i=a;i<=b;i++)
#define forr(i,a,b) for(register long long i=a;i>=b;i--)
#define forll(i,a,b,c) for(register long long i=a;i<=b;i+=c)
#define forrr(i,a,b,c) for(register long long i=a;i>=b;i-=c)
#define lc(x) x<<1
#define rc(x) x<<1|1
#define mid ((l+r)>>1)
#define cin(x) scanf("%lld",&x)
#define cout(x) printf("%lld",x)
#define lowbit(x) (x&-x)
#define pb push_back
#define pf push_front
#define IOS ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);
#define endl '\n'
#define QwQ return 0;
#define ll long long
#define ull unsigned long long
#define lcm(x,y) x/__gcd(x,y)*y
#define Sum(x,y) 1ll*(x+y)*(y-x+1)/2
#define aty cout<<"Yes\n";
#define atn cout<<"No\n";
#define cfy cout<<"YES\n";
#define cfn cout<<"NO\n";
#define xxy cout<<"yes\n";
#define xxn cout<<"no\n";
#define printcf(x) x?cout<<"YES\n":cout<<"NO\n";
#define printat(x) x?cout<<"Yes\n":cout<<"No\n";
#define printxx(x) x?cout<<"yes\n":cout<<"no\n";
ll t;
ll n,m;
ll a[200010],b[200010],L=1,ans,sum;
void solve()
{
	cin>>n>>m;
	forl(i,1,n)
		cin>>a[i];
	forl(i,1,m)
		cin>>b[i];
	sort(a+1,a+1+n);
	sort(b+1,b+1+m);
	forl(i,1,m)
		while(L<=n)
		{
			if(a[L]>=b[i])
			{
				sum++;
				ans+=a[L];
				L++;
				break;
			}
			else
				L++;
		}
	if(sum!=m)
		cout<<-1<<endl;
	else
		cout<<ans<<endl;
}
int main()
{
	IOS;
	t=1;
 //	cin>>t;
	while(t--)
		solve();
    /******************/
	/*while(L<q[i].l) */
	/*    del(a[L++]);*/
	/*while(L>q[i].l) */
	/*    add(a[--L]);*/
	/*while(R<q[i].r) */
	/*	  add(a[++R]);*/
	/*while(R>q[i].r) */
	/*    del(a[R--]);*/
    /******************/
	QwQ;
}

E

\(dp{i,j}\) 表示選前 \(i\) 個字元到考慮到第 \(j\) 位的方案數。

使用組合數轉移。

點選檢視程式碼
/*
Tips:
你陣列開小了嗎?
你MLE了嗎?
你覺得是貪心,是不是該想想dp?
一個小時沒調出來,是不是該考慮換題?
打 cf 不要用 umap!!!

記住,rating 是身外之物。

該衝正解時衝正解!

Problem:

演算法:

思路:

*/
#include<bits/stdc++.h>
using namespace std;
//#define map unordered_map
#define forl(i,a,b) for(register long long i=a;i<=b;i++)
#define forr(i,a,b) for(register long long i=a;i>=b;i--)
#define forll(i,a,b,c) for(register long long i=a;i<=b;i+=c)
#define forrr(i,a,b,c) for(register long long i=a;i>=b;i-=c)
#define lc(x) x<<1
#define rc(x) x<<1|1
#define mid ((l+r)>>1)
#define cin(x) scanf("%lld",&x)
#define cout(x) printf("%lld",x)
#define lowbit(x) (x&-x)
#define pb push_back
#define pf push_front
#define IOS ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);
#define endl '\n'
#define QwQ return 0;
#define ll long long
#define ull unsigned long long
#define lcm(x,y) x/__gcd(x,y)*y
#define Sum(x,y) 1ll*(x+y)*(y-x+1)/2
#define aty cout<<"Yes\n";
#define atn cout<<"No\n";
#define cfy cout<<"YES\n";
#define cfn cout<<"NO\n";
#define xxy cout<<"yes\n";
#define xxn cout<<"no\n";
#define printcf(x) x?cout<<"YES\n":cout<<"NO\n";
#define printat(x) x?cout<<"Yes\n":cout<<"No\n";
#define printxx(x) x?cout<<"yes\n":cout<<"no\n";
ll t;
ll n;
ll mod=998244353;
ll a[60],C[2010][2010];
ll dp[2010][2010];
ll f(ll x,ll y){
	return C[x+y-1][y-1];
}
ll ans;
void init()
{
	forl(i,0,2009)
	{
		C[i][0]=C[i][i]=1;
		forl(j,1,i-1)
			C[i][j]=(C[i-1][j]+C[i-1][j-1])%mod;
	}
	dp[0][0]=1;
}
void solve()
{
	init();
	cin>>n;
	forl(i,1,26)
		cin>>a[i];
	forl(i,1,26)
		forl(j,0,n)
			forl(k,0,min(j,a[i]))
				dp[i][j]+=dp[i-1][j-k]%mod*f(k,j-k+1)%mod,dp[i][j]%=mod;
	forl(i,1,n)
		ans+=dp[26][i],ans%=mod;
	cout<<ans<<endl;
}
int main()
{
	IOS;
	t=1;
 //	cin>>t;
	while(t--)
		solve();
    /******************/
	/*while(L<q[i].l) */
	/*    del(a[L++]);*/
	/*while(L>q[i].l) */
	/*    add(a[--L]);*/
	/*while(R<q[i].r) */
	/*	  add(a[++R]);*/
	/*while(R>q[i].r) */
	/*    del(a[R--]);*/
    /******************/
	QwQ;
}

G

link

相關文章