Codeforces Beta Round #44 (Div. 2)
http://codeforces.com/contest/47
A
1 #include<bits/stdc++.h> 2 using namespace std; 3 #define lson l,mid,rt<<1 4 #define rson mid+1,r,rt<<1|1 5 #define sqr(x) ((x)*(x)) 6 #define pb push_back 7 #define maxn 1000005 8 typedef long long ll; 9 typedef unsigned long long ull; 10 11 12 13 14 int main(){ 15 #ifndef ONLINE_JUDGE 16 // freopen("input.txt","r",stdin); 17 #endif 18 std::ios::sync_with_stdio(false); 19 map<int,int>mp; 20 for(int i=1;i<=500;i++){ 21 mp[i*(i+1)/2]=1; 22 } 23 int n; 24 cin>>n; 25 if(mp[n]) cout<<"YES"<<endl; 26 else cout<<"NO"<<endl; 27 28 }
B
1 #include<bits/stdc++.h> 2 using namespace std; 3 #define lson l,mid,rt<<1 4 #define rson mid+1,r,rt<<1|1 5 #define sqr(x) ((x)*(x)) 6 #define pb push_back 7 #define maxn 1000005 8 typedef long long ll; 9 typedef unsigned long long ull; 10 11 12 struct sair{ 13 char ch; 14 int v; 15 bool operator<(const sair &b)const{ 16 return v>b.v; 17 } 18 }s; 19 20 int main(){ 21 #ifndef ONLINE_JUDGE 22 freopen("input.txt","r",stdin); 23 #endif 24 std::ios::sync_with_stdio(false); 25 int a,b,c; 26 string str; 27 map<char,int>mp; 28 mp['A']++; 29 mp['B']++; 30 mp['C']++; 31 for(int i=1;i<=3;i++){ 32 cin>>str; 33 if(str[1]=='>'){ 34 mp[str[2]]++; 35 } 36 else{ 37 mp[str[0]]++; 38 } 39 } 40 vector<sair>ve; 41 int book[5]; 42 memset(book,0,sizeof(book)); 43 for(map<char,int>::iterator it=mp.begin();it!=mp.end();it++){ 44 s.ch=it->first; 45 s.v=it->second; 46 if(book[s.v]){ 47 cout<<"Impossible"<<endl; 48 return 0; 49 } 50 book[s.v]=1; 51 ve.push_back(s); 52 } 53 sort(ve.begin(),ve.end()); 54 for(int i=0;i<ve.size();i++){ 55 cout<<ve[i].ch; 56 } 57 58 }
C
大模拟
1 #include<bits/stdc++.h> 2 using namespace std; 3 #define lson l,mid,rt<<1 4 #define rson mid+1,r,rt<<1|1 5 #define sqr(x) ((x)*(x)) 6 #define pb push_back 7 #define maxn 1000005 8 typedef long long ll; 9 typedef unsigned long long ull; 10 11 vector<string>ans; 12 string s[6]; 13 bool add(char &a,char b){if (a!='.'&&a!=b)return 0;a=b;return 1;} 14 15 int main(){ 16 #ifndef ONLINE_JUDGE 17 freopen("input.txt","r",stdin); 18 #endif 19 std::ios::sync_with_stdio(false); 20 for (int i=0;i<=5;i++)cin>>s[i]; 21 sort(s,s+6); 22 do{ 23 vector<string>v(s[0].size(),string(s[1].size(),'.')); 24 if (s[0].size()!=s[4].size()+s[3].size()-1) continue; 25 if (s[1].size()!=s[2].size()+s[5].size()-1) continue; 26 bool fl=1; 27 for (int i=0;i<s[0].size();i++)fl&=add(v[i][s[2].size()-1],s[0][i]); 28 for (int i=0;i<s[1].size();i++)fl&=add(v[s[3].size()-1][i],s[1][i]); 29 for (int i=0;i<s[2].size();i++)fl&=add(v[0][i],s[2][i]); 30 for (int i=0;i<s[3].size();i++)fl&=add(v[i][0],s[3][i]); 31 for (int i=0;i<s[4].size();i++)fl&=add(v[s[3].size()-1+i][s[1].size()-1],s[4][i]); 32 for (int i=0;i<s[5].size();i++)fl&=add(v[s[0].size()-1][s[2].size()-1+i],s[5][i]); 33 if (!fl) continue; 34 if (ans.empty()||v<ans) ans=v; 35 }while (next_permutation(s,s+6)); 36 if (ans.empty()) cout<<"Impossible"<<endl; 37 else for(auto i:ans) cout<<i<<endl; 38 }
D
暴力搜索
1 #include<bits/stdc++.h> 2 using namespace std; 3 #define lson l,mid,rt<<1 4 #define rson mid+1,r,rt<<1|1 5 #define sqr(x) ((x)*(x)) 6 #define pb push_back 7 #define maxn 1000005 8 typedef long long ll; 9 typedef unsigned long long ull; 10 11 char s[12][40]; 12 int c[12],n,m,ans; 13 void dfs(int t) 14 { 15 int i,j; 16 for(i=0;i<m;i++) 17 if(c[i]<0)return ; 18 if(t>=n) 19 { 20 for(i=0;i<m;i++) 21 if(c[i]>0) return ; 22 ans++; 23 return ; 24 } 25 for(i=0;i<=1;i++) 26 { 27 for(j=0;j<m;j++) 28 if(s[j][t]==(i+'0'))c[j]--; 29 dfs(t+1); 30 for(j=0;j<m;j++) 31 if(s[j][t]==(i+'0'))c[j]++; 32 } 33 } 34 35 int main(){ 36 #ifndef ONLINE_JUDGE 37 freopen("input.txt","r",stdin); 38 #endif 39 std::ios::sync_with_stdio(false); 40 cin>>n>>m; 41 for(int i=0;i<m;i++)cin>>s[i]>>c[i]; 42 ans=0; 43 dfs(0); 44 cout<<ans<<endl; 45 }
E
几何，把子弹按角度从小到大排序，然后模拟
1 #include<bits/stdc++.h> 2 using namespace std; 3 #define lson l,mid,rt<<1 4 #define rson mid+1,r,rt<<1|1 5 #define sqr(x) ((x)*(x)) 6 #define pb push_back 7 #define maxn 1000005 8 typedef long long ll; 9 typedef unsigned long long ull; 10 11 const double g=9.8; 12 double v,al[10005],ss[10005],cc[10005]; 13 int d[10005]; 14 pair<double,double> w[100005]; 15 double x[10005]; 16 17 double run(double x,double alpha) 18 { 19 return (v*sin(alpha)+v*sin(alpha)-g*x/(v*cos(alpha)))*x/(v*cos(alpha))/2; 20 } 21 bool cmp(const int &a,const int &b) 22 { 23 return al[a]<al[b]; 24 } 25 26 int main(){ 27 #ifndef ONLINE_JUDGE 28 freopen("input.txt","r",stdin); 29 #endif 30 std::ios::sync_with_stdio(false); 31 int n,m; 32 scanf("%d%lf",&n,&v); 33 for(int i=1;i<=n;i++) 34 scanf("%lf",&al[d[i]=i]),cc[i]=cos(al[i]),ss[i]=sin(al[i]); 35 sort(d+1,d+1+n,cmp); 36 scanf("%d",&m); 37 for(int i=1;i<=m;i++) 38 scanf("%lf%lf",&w[i].first,&w[i].second); 39 sort(w+1,w+1+m); 40 int j=1; 41 for(int i=1;i<=n;i++) 42 { 43 while(j<=m&&run(w[j].first,al[d[i]])>w[j].second)j++; 44 if(j>m||run(w[j].first,al[d[i]])<0) 45 { 46 x[d[i]]=v*ss[d[i]]/g*2*v*cc[d[i]]; 47 continue; 48 } 49 x[d[i]]=w[j].first; 50 } 51 for(int i=1;i<=n;i++) 52 printf("%.9lf %.9lf ",x[i],run(x[i],al[i])); 53 }