太菜了，刷刷NOIP題玩玩。

今天的題好像以前有做過（霧）

A.

#include<bits/stdc++.h>
typedef long long ll;
int n,q,phi,p[210],cnt;
ll x;
inline ll sqr(ll x){return x*x;}
ll fpow(ll x,ll p){
    ll ans=1;
    for(;p;p>>=1,x=x*x%n)if(p&1)ans=(ans*x)%n;
    return ans;
}
inline ll read(){
    ll f=1,x=0;char ch;
    
 
do{ch=getchar();if(ch==‘-‘)f=-1;}while(ch<‘0‘||ch>‘9‘);
    do{x=x*10+ch-‘0‘;ch=getchar();}while(ch>=‘0‘&&ch<=‘9‘);
    return f*x;
}
int main(){
    n=read();q=read();phi=n;int qwq=n;
    for(int i=2;i*i<=n;i++){
        if(n%i==0)phi=phi/i*(i-1);
        while(n%i==0)n/=i;
    }
    
 
if(n!=1)phi=phi/n*(n-1);
    p[cnt=1]=1;n=qwq;
    for(int i=2;i*i<=n;i++)if(phi%i==0){p[++cnt]=i;if(i*i!=phi)p[++cnt]=phi/i;}
    while(q--){
        x=read();char ch=‘1‘;
        if(fpow(x,phi)!=1){putchar(‘0‘);continue;}
        for(int j=1;j<=cnt;j++)if(fpow(x,p[j])==1){ch=‘0‘;break;}
        putchar(ch);
    }
}
 

B.

#include<bits/stdc++.h>
#define N 100010
const int yql=1e9+7;
typedef long long ll;
using namespace std;
struct Edge{int u,v,next;}G[2*N];
int tot=0,head[4*N],fa[N],n;
ll ans,w[N],sumv[N];
void addedge(int u,int v){
    G[++tot].u=u;G[tot].v=v;G[tot].next=head[u];head[u]=tot;
    G[++tot].u=v;G[tot].v=u;G[tot].next=head[v];head[v]=tot;
}
inline ll read(){
    int f=1,x=0;char ch;
    do{ch=getchar();if(ch==‘-‘)f=-1;}while(ch<‘0‘||ch>‘9‘);
    do{x=x*10+ch-‘0‘;ch=getchar();}while(ch>=‘0‘&&ch<=‘9‘);
    return f*x;
}
void dfs(int u,int f){
    for(int i=head[u];i;i=G[i].next){
        int v=G[i].v;if(v==f)continue;
        fa[v]=u;dfs(v,u);
        sumv[u]=(sumv[u]+sumv[v])%yql;
    }
    ll tmp=(sumv[u]*2LL+w[u])%yql*w[u]%yql;
    for(int i=head[u];i;i=G[i].next){
        int v=G[i].v;if(v==f)continue;
        tmp=(tmp+(sumv[u]+yql-sumv[v])%yql*sumv[v])%yql;
    }
    //printf("%lld\n",tmp);
    ans=(ans+tmp*w[u])%yql;
    sumv[u]=(sumv[u]+w[u])%yql;
}
int main(){
    n=read();w[1]=read();
    for(int i=2;i<=n;i++){
        int u=read();w[i]=read();
        i[w]%=yql;
        addedge(u,i);
    }
    dfs(1,0);
    //for(int i=1;i<=n;i++)printf("%lld ",sumv[i]);puts("");
    printf("%lld\n",ans%yql);
    return 0;
}

C.

#include<bits/stdc++.h>
const int N=200010;
using namespace std;
int n,m,fa[N],cnt=0;
map<string,int> mps;
struct Edge{int u,v,w;}G[N];
char s[100],p[100];
bool operator <(Edge x,Edge y){return x.w<y.w;}
inline int find(int x){return x==fa[x]?x:fa[x]=find(fa[x]);}
inline int read(){
    int f=1,x=0;char ch;
    do{ch=getchar();if(ch==‘-‘)f=-1;}while(ch<‘0‘||ch>‘9‘);
    do{x=x*10+ch-‘0‘;ch=getchar();}while(ch>=‘0‘&&ch<=‘9‘);
    return f*x;
}
int main(){
    n=read();m=read();
    for(int i=1;i<=m;i++){
        scanf("%d%s%s",&G[i].w,s,p);
        string qwq=string(s);
        if(mps[qwq]==0)mps[qwq]=++cnt;
        G[i].u=mps[qwq];
        qwq=string(p);
        if(mps[qwq]==0)mps[qwq]=++cnt;
        G[i].v=mps[qwq];
    }
    for(int i=1;i<=cnt;i++)fa[i]=i;
    sort(G+1,G+m+1);
    for(int i=1;i<=m&&n;i++){
        int x=find(G[i].u),y=find(G[i].v);
        if(x!=y){fa[x]=y;--n;printf("%d\n",G[i].w);}
    }
    for(int i=1;i<=n;i++)puts("INF");
}

【jzoj2017.8.21提高組A】