1 //CF #286 Div.2 A 2 #include<vector> 3 #include<string> 4 #include<cstdio> 5 #include<cstring> 6 #include<cstdlib> 7 #include<iostream> 8 #include<algorithm> 9 #define rep(i,n) for(int i=0;i<n;++i)10 #define F(i,j,n) for(int i=j;i<=n;++i)11 #define D(i,j,n) for(int i=j;i>=n;--i)12 using namespace std;13 const int N=10086;14 15 void read(int &v){16     v=0;int sign=1; char ch=getchar();17     while(ch<‘0‘ || ch>‘9‘) {if (ch==‘-‘) sign=-1; ch=getchar();}18     while(ch>=‘0‘&&ch<=‘9‘){v=v*10+ch-‘0‘; ch=getchar();}19     v*=sign;20 }21 /****************tamplate***********************/22 23 string s,s1;24 bool check(int pos,char ch){25     s1="";26     rep(i,pos) s1+=s[i];27     s1+=ch;28     F(i,pos,s.length()-1) s1+=s[i];29 30     for(int l=0,r=s1.length()-1;l<r;l++,r--)31         if (s1[l]!=s1[r]) return 0;32     return 1;33 }34 35 int main(){36     ios::sync_with_stdio(false);37     cin >> s;38     int l=0,r=s.length(),pos=-1;39 40     bool sign=1;41     F(i,0,s.length())42         rep(j,26) if (check(i,j+‘a‘)) {43             cout <<s1<<endl;44             return 0;45         }46     printf("NA");47     return 0;48 }

 1 //CF #286 Div.2 B 2 #include<vector> 3 #include<cstdio> 4 #include<cstring> 5 #include<cstdlib> 6 #include<vector> 7 #include<iostream> 8 #include<algorithm> 9 #define rep(i,n) for(int i=0;i<n;++i)10 #define F(i,j,n) for(int i=j;i<=n;++i)11 #define D(i,j,n) for(int i=j;i>=n;--i)12 #define pb push_back13 using namespace std;14 const int N=110;15 16 void read(int &v){17     v=0;int sign=1; char ch=getchar();18     while(ch<‘0‘ || ch>‘9‘) {if (ch==‘-‘) sign=-1; ch=getchar();}19     while(ch>=‘0‘&&ch<=‘9‘){v=v*10+ch-‘0‘; ch=getchar();}20     v*=sign;21 }22 /****************tamplate***********************/23 int n,m,cnt=0;24 struct edge{25     int from,to,color;26 };27 vector<edge>E;28 vector<int>G[N];29 void add(int x,int y,int z){30     E.pb((edge){x,y,z});31     E.pb((edge){y,x,z});32     int m=E.size();33     G[x].pb(m-2);34     G[y].pb(m-1);35 }36 37 bool vis[N],yes[N];38 void dfs(int x,int fa,int y,int col){39     if (x==y) {yes[col]=1; return;}40     vis[x]=1;41     rep(i,G[x].size()){42         edge&e=E[G[x][i]];43         if (e.color==col && vis[e.to]==0) dfs(e.to,x,y,col);44     }45 }46 47 int main(){48     read(n); read(m);49     int x,y,z;50     F(i,1,m){51         read(x); read(y); read(z);52         add(x,y,z);53     }54     int Q;55     read(Q);56     F(i,1,Q){57         read(x);58         read(y);59         memset(yes,0,sizeof yes);60         rep(i,G[x].size()){61             memset(vis,0,sizeof vis);62             dfs(E[G[x][i]].to,x,y,E[G[x][i]].color);63         }64         int cnt=0;65         F(i,1,m) cnt+=yes[i];66         printf("%d\n",cnt);67     }68     return 0;69 }