Codeforces Beta Round #79 (Div. 2 Only)
http://codeforces.com/contest/102
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 eb emplace_back 8 #define maxn 13000005 9 #define eps 1e-8 10 #define pi acos(-1.0) 11 #define rep(k,i,j) for(int k=i;k<j;k++) 12 typedef long long ll; 13 typedef pair<int,int> pii; 14 typedef pair<long long,int>pli; 15 typedef pair<char,int> pci; 16 typedef pair<pair<int,string>,pii> ppp; 17 typedef unsigned long long ull; 18 const long long MOD=1e9+7; 19 /*#ifndef ONLINE_JUDGE 20 freopen("1.txt","r",stdin); 21 #endif */ 22 23 int a[105][105]; 24 int v[105]; 25 26 int main(){ 27 #ifndef ONLINE_JUDGE 28 // freopen("1.txt","r",stdin); 29 #endif 30 std::ios::sync_with_stdio(false); 31 int n,m; 32 cin>>n>>m; 33 for(int i=1;i<=n;i++) cin>>v[i]; 34 int uu,vv; 35 for(int i=1;i<=m;i++){ 36 cin>>uu>>vv; 37 a[uu][vv]=a[vv][uu]=1; 38 } 39 int ans=0x3f3f3f3f; 40 for(int i=1;i<=n;i++){ 41 for(int j=1;j<=n;j++){ 42 for(int k=1;k<=n;k++){ 43 if(i==j||j==k||k==i) continue; 44 if(a[i][j]==a[j][k]&&a[j][k]==a[k][i]&&a[k][i]==1){ 45 46 ans=min(ans,v[i]+v[j]+v[k]); 47 } 48 } 49 } 50 } 51 if(ans==0x3f3f3f3f) cout<<-1; 52 else 53 cout<<ans<<endl; 54 }
B
暴力
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 eb emplace_back 8 #define maxn 13000005 9 #define eps 1e-8 10 #define pi acos(-1.0) 11 #define rep(k,i,j) for(int k=i;k<j;k++) 12 typedef long long ll; 13 typedef pair<int,int> pii; 14 typedef pair<long long,int>pli; 15 typedef pair<char,int> pci; 16 typedef pair<pair<int,string>,pii> ppp; 17 typedef unsigned long long ull; 18 const long long MOD=1e9+7; 19 /*#ifndef ONLINE_JUDGE 20 freopen("1.txt","r",stdin); 21 #endif */ 22 23 24 int main(){ 25 #ifndef ONLINE_JUDGE 26 // freopen("1.txt","r",stdin); 27 #endif 28 std::ios::sync_with_stdio(false); 29 string str; 30 cin>>str; 31 int ans=0; 32 while(str.length()!=1){ 33 int tmp=0; 34 for(int i=0;i<str.length();i++) tmp+=str[i]-'0'; 35 ans++; 36 str=to_string(tmp); 37 } 38 cout<<ans<<endl; 39 }
C
贪心
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 eb emplace_back 8 #define maxn 13000005 9 #define eps 1e-8 10 #define pi acos(-1.0) 11 #define rep(k,i,j) for(int k=i;k<j;k++) 12 typedef long long ll; 13 typedef pair<int,int> pii; 14 typedef pair<long long,int>pli; 15 typedef pair<int,char> pic; 16 typedef pair<pair<int,string>,pii> ppp; 17 typedef unsigned long long ull; 18 const long long MOD=1e9+7; 19 /*#ifndef ONLINE_JUDGE 20 freopen("1.txt","r",stdin); 21 #endif */ 22 23 int book[35]; 24 25 int main(){ 26 #ifndef ONLINE_JUDGE 27 // freopen("1.txt","r",stdin); 28 #endif 29 std::ios::sync_with_stdio(false); 30 string str; 31 int n; 32 cin>>str>>n; 33 for(int i=0;i<str.length();i++){ 34 book[str[i]-'a']++; 35 } 36 if(str.length()<=n) cout<<0<<endl<<endl; 37 else{ 38 set<char>se; 39 vector<pic>ve; 40 for(int i=0;i<26;i++){ 41 ve.pb({book[i],'a'+i}); 42 } 43 sort(ve.begin(),ve.end()); 44 for(int i=0;i<ve.size();i++){ 45 if(ve[i].first<=n){ 46 n-=ve[i].first; 47 se.insert(ve[i].second); 48 } 49 else{ 50 break; 51 } 52 } 53 string s=""; 54 for(int i=0;i<str.length();i++){ 55 if(se.count(str[i])) continue; 56 else s+=str[i]; 57 } 58 set<char>ss; 59 for(int i=0;i<s.length();i++){ 60 ss.insert(s[i]); 61 } 62 cout<<ss.size()<<endl<<s<<endl; 63 } 64 }
D
树状数组+离散化
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 eb emplace_back 8 #define maxn 13000005 9 #define eps 1e-8 10 #define pi acos(-1.0) 11 #define rep(k,i,j) for(int k=i;k<j;k++) 12 typedef long long ll; 13 typedef pair<int,int> pii; 14 typedef pair<long long,int>pli; 15 typedef pair<int,char> pic; 16 typedef pair<pair<int,string>,pii> ppp; 17 typedef unsigned long long ull; 18 const long long MOD=1e9+7; 19 /*#ifndef ONLINE_JUDGE 20 freopen("1.txt","r",stdin); 21 #endif */ 22 23 int n,m; 24 25 map<int,int>tree; 26 27 int lowbit(int x){ 28 return x&(-x); 29 } 30 31 void add(int x,int v){ 32 while(x<=n+1){ 33 tree[x]=(tree[x]+v)%MOD; 34 x+=lowbit(x); 35 } 36 } 37 38 int getsum(int x){ 39 int ans=0; 40 while(x){ 41 ans=(ans+tree[x])%MOD; 42 x-=lowbit(x); 43 } 44 return ans; 45 } 46 vector<pii>ve; 47 48 int main(){ 49 #ifndef ONLINE_JUDGE 50 // freopen("1.txt","r",stdin); 51 #endif 52 std::ios::sync_with_stdio(false); 53 cin>>n>>m; 54 int a,b; 55 for(int i=1;i<=m;i++){ 56 cin>>a>>b; 57 ve.pb({b+1,a+1}); 58 } 59 sort(ve.begin(),ve.end()); 60 add(1,1); 61 for(int i=0;i<m;i++){ 62 int s=ve[i].second,t=ve[i].first; 63 int tmp=getsum(t-1)-getsum(s-1); 64 tmp=(tmp%MOD+MOD)%MOD; 65 add(t,tmp); 66 } 67 int ans=getsum(n+1)-getsum(n); 68 cout<<(ans%MOD+MOD)%MOD<<endl; 69 }