CCF CSP 第十九次认证

机器学习派上了用场

#include<bits/stdc++.h>
using namespace std;
int getsign(long long x){
	return x<0?-1:1;
}
int main(int argc, char const *argv[])
{
	int n;
	int t;
	cin>>n>>t;
	map<char, vector<pair<long long,long long>>>  p;
	int x,y;
	char c;
	for(int i=0; i<n; i++){
		cin>>x>>y>>c;
		p[c].push_back(make_pair(x,y));

	}
	while(t--){
		long long a1,a2,a3;
		cin>>a1>>a2>>a3;
		long long A = a1+p['A'][0].first*a2+p['A'][0].second*a3;
		long long B = a1+p['B'][0].first*a2+p['B'][0].second*a3;
		if(getsign(A)==getsign(B)){
			cout<<"No"<<endl;
			continue;
		}
		bool flag = false;
		for(auto pp:p['A']){
			long long temp = a1+pp.first*a2+pp.second*a3;
			if(getsign(temp)*getsign(A)<0){
				flag = true;
				break; 
			}
		}
		for(auto pp:p['B']){
			long long temp = a1+pp.first*a2+pp.second*a3;
			if(getsign(temp)*getsign(B)<0){
				flag = true;
				break; 
			}
		}
		if(flag)
			cout<<"No"<<endl;
		else
			cout<<"Yes"<<endl;
	}

	return 0;
}

双指针

#include<bits/stdc++.h>
using namespace std;


int main(int argc, char const *argv[])
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	int n;
	cin>>n;
	int a, b;
	cin>>a>>b;
	vector<pair<long long,long long>> X(a),Y(b);
	long long ans = 0;
	long long x,y;
	for (int i = 0; i < a; ++i)
	{
		cin>>x>>y;
		X[i] = make_pair(x,y);
	}
	for (int i = 0; i < b; ++i)
	{
		cin>>x>>y;
		Y[i] = make_pair(x,y);
	}
	sort(X.begin(), X.end());
	sort(Y.begin(), Y.end());
	int i=0,j=0;
	while(i<a&&j<b){
		if(X[i].first==Y[j].first)
			ans += X[i++].second* Y[j++].second;
		else if(X[i].first<Y[j].first)
			i++;
		else 
			j++;
	}
	cout<<ans<<endl;
	return 0;
}

阅读理解题，后面太麻烦了
先骗四十分

#include<bits/stdc++.h>

using namespace std;

string gets1(string s){
	string res = "";
	int l = 0;
	int r = s.length()-1;
	while(l<=r&&s[l]==' ') l++;
	while(l<=r&&s[r]==' ') r--;
	while(l<=r)
		res += s[l++];
	return res;
}
int main(int argc, char const *argv[])
{
	string s;
	int n;
	// freopen("test.dat","r", stdin);
	cin>>n;
	// getchar();
	int ans = 0;
	int state = 0;
	string temp = "";
	int len = 0;
	while(getline(cin,s)){
		// cout<<s;
		string res = gets1(s);
		if(res.length()==0){ //遇到了一个新的段落
			if(state==0)
				continue;
			for(int i=0; i<temp.length(); i++){
				if(len%n==0&&temp[i]==' ')
					continue;
				else{
					len++;
				}
			}
			// cout<<len<<endl;
			ans += len/n + ((len%n)>0)+1;
			temp = "";
			len = 0;
			state = 0;
			// cout<<ans<<endl;
		}else{
			temp+= " "+res;
			state = 1;
		}
	}
	// cout<<len<<endl;ans += len/n + ((len%n)>0)+1;
	if(temp.length()){
		// if(len%n!=0)
		// 		cout<<endl;
			for(int i=0; i<temp.length(); i++){
						if(len%n==0&&temp[i]==' ')
							continue;
						else{
							len++;
					}
		}
		ans += len/n + ((len%n)>0)+1;
	}
	cout<<ans-1<<endl;
	return 0;
}
// 段落： 去掉每行首位的连续空格
//		 每行开头如果是空格，那么要去掉空格
// 		 如果有多行， 则将各行用一个空格链接起来
//     段落与段落之间或者段落与空行之间应该空出一行间距

// 项目：
//   

矩阵快速幂
能过96分，第一次接触矩阵快速幂
判重需要仔细考虑，两个的时候只能考虑单个数字生成
和相邻数字生成的新的对

#include<bits/stdc++.h>

using namespace std;

const long long mod = 998244353;

vector<vector<long long>> se={ 
        {0,0,1,0,0,0,0,0,0,0,0,0,0,0},  
        {1,0,0,0,0,0,0,0,0,0,0,0,0,0},  
        {0,1,0,1,0,0,0,0,0,0,0,0,0,0},  
        {0,0,1,1,0,0,0,0,0,0,0,0,0,0},  
        {0,0,1,0,0,0,0,0,0,0,0,0,0,0},  
        {0,0,0,0,1,0,0,0,0,0,0,0,0,0},  
        {0,0,0,0,0,0,0,0,0,0,0,1,0,0},  
        {0,0,0,0,0,0,0,0,0,0,1,0,0,0},  
        {0,0,0,0,0,1,0,0,0,0,0,0,1,0},  
        {0,0,0,0,0,0,0,1,0,0,0,0,0,0},  
        {0,0,0,0,0,0,1,0,0,0,0,0,0,0},  
        {0,0,0,1,0,0,0,0,0,0,0,0,0,1},  
        {0,0,0,0,0,0,0,0,1,0,0,0,0,0},  
        {0,0,0,0,0,0,0,0,0,1,0,0,0,0}  
    };

// vector<vector<long long>> seini = {{1,0,0,0,0,0,0,0,0,0,0,0,0,0}};
vector<long long> fi = {1,2,4,6,16,26,41,44,46,61,62,64,66,42};

vector<vector<long long>> mmul(vector<vector<long long >> a, vector<vector<long long>> b){
	int n = a.size();
	int m = a[0].size();
	int mm = b[0].size();
	vector<vector<long long>> aa(n, vector<long long>(mm, 0LL));
	for(int i=0; i<n; i++){
		for(int j=0;  j<mm;j++){
			for(int k=0; k<m; k++){
				aa[i][j] = ((aa[i][j]%mod)+((a[i][k]%mod)*(b[k][j]%mod))%mod)%mod;
			}
		}
	}
	return aa;
}
vector<vector<long long>> matrix_mul(vector<vector<long long>> a, int t){
	vector<vector<long long>> res(14, vector<long long>(14, 0LL));
	for(int i=0; i<14; i++){
		for(int j=0; j<14; j++){
			res[i][j]=0;
			if(i==j)
				res[i][j]=1LL;
		}
	}
	while(t){
		if(t&1){
			res = mmul(a,res);
		}
		a = mmul(a,a);
		t = t>>1;
	}
	return res;
}
int main()
{
	int n;
	cin>>n;
	string s;
	cin>>s;
	int targ = stoi(s);
	se = matrix_mul(se, n);
	for(int i=0; i<14; i++){
		if(fi[i]==targ){
			cout<<se[i][0]<<endl;
			return 0;
		}
	}
	cout<<0<<endl;
	return 0;
}

只会dfs暴力前四十分，但是不知道为啥只能过三十分
离谱了，想了一天也没看出来哪里错了，随缘了

#include<bits/stdc++.h>
#define LL long long
using namespace std;

// 0表示不选
// 1表示选边界
// 2表示不选边界
vector<vector<LL>> a(1100, vector<LL>(5,0));

LL n, m;
LL used[1100];
LL buy[1100];
LL ans = 0;
vector<pair<LL,pair<LL, LL>>> sss;

bool judge(){
	for(auto ss:sss){
		if(ss.second.second==1){
			if(used[ss.first]&&!used[ss.second.first])
				return false;
		}else{
			if(used[ss.first]==1&&!used[ss.second.first])
				return false;
		}
	}
	return true;
}
LL cal(){
	LL res = 0;
	for(LL i=1; i<=n; i++){
		res += buy[i];
	}
	return res;

}
LL cal_2(LL i, LL x){
	return a[i][2]*x*x+a[i][3]*x+a[i][4];
}
void dfs(LL i){
	if(i==n+1){
		if(judge())
			ans = max(ans, cal());
		// cout<<endl<<cal()<<endl;
		return;
	}
	for(LL t=0; t<3; t++){
		used[i]=t;
		buy[i]=0;
		if(t==1){
			buy[i] = max(cal_2(i,a[i][0]), cal_2(i,a[i][1]));
		}
		else if(t==2){
			if(a[t][2]==0){
				buy[i]=max(cal_2(i,a[i][0]+1), cal_2(i,a[i][1]-1));
			}else{
				buy[i]=max(cal_2(i,a[i][0]+1), cal_2(i,a[i][1]-1));
				LL temp = (-a[i][1]/(2LL*a[i][0]));
				if(temp>a[i][0]&&temp<a[i][1])
					buy[i] = max(buy[i], cal_2(i, temp));
				temp -= 1;
				if(temp>a[i][0]&&temp<a[i][1])
					buy[i] = max(buy[i], cal_2(i, temp));
				temp += 2;
				if(temp>a[i][0]&&temp<a[i][1])
					buy[i] = max(buy[i], cal_2(i, temp));
			}
		}
		dfs(i+1);
	}
}
int main()
{
	ans = 0;
	memset(used,0,sizeof used);
	memset(buy,0,sizeof buy);
	cin>>n>>m;
	for(LL i=1; i<=n; i++){
		cin>>a[i][0]>>a[i][1]>>a[i][2]>>a[i][3]>>a[i][4];
	}
	LL x,y,c;
	for(LL i=0; i<m; i++){
		cin>>c>>x>>y;
		sss.push_back(make_pair(x,make_pair(y,c)));
	}
	dfs(1);
	cout<<ans<<endl;
	return 0;
}

离谱的，不知道九月考试能考多少分