1.数学老师的报复
#include<iostream> #include<cstdio> using namespace std; int cnt; short int f[55000000]; long long a,b,n; long long qread(){ long long i=0,j=1; char ch=getchar(); while(ch<'0'||ch>'9'){if(ch=='-')j=-1;ch=getchar();} while(ch<='9'&&ch>='0')i=i*10+ch-'0',ch=getchar(); return i*j; } int main(){ freopen("attack.in","r",stdin);freopen("attack.out","w",stdout); // freopen("Cola.in","r",stdin); a=qread();b=qread();n=qread(); cnt=2;f[1]=1;f[2]=1; while(1){ cnt++; f[cnt]=(a*f[cnt-1]+b*f[cnt-2])%7; if(f[cnt]==1&&f[cnt-1]==1)break; if(cnt==n)break; } if(n<=cnt){cout<<f[n];return 0;} cnt-=2; long long ans=n%cnt; if(ans==0)ans=cnt; ans=f[ans]; cout<<ans; }
#include<bits/stdc++.h> #define ll long long using namespace std; ll n,aa,bb; struct matrix{ ll a[2][2]; matrix(){memset(a,0,sizeof(a));} matrix(ll b[2][2]) {for(int i=0;i<2;i++)for(int j=0;j<2;j++)a[i][j]=b[i][j];} matrix operator * (matrix b) { matrix ans; for(int i=0;i<2;i++) for(int j=0;j<2;j++) for(int k=0;k<2;k++) ans.a[i][j]=(ans.a[i][j]+a[i][k]*b.a[k][j])%7; ans.a[0][0]%=7; return ans; } }S,T; inline ll read() { ll x=0,f=1;char c=getchar(); while(c<'0'||c>'9'){if(c=='-')f=-1;c=getchar();} while(c>='0'&&c<='9'){x=x*10+c-'0';c=getchar();} return x*f; } int main() { freopen("attack.in","r",stdin); freopen("attack.out","w",stdout); while(scanf("%lld%lld%lld",&aa,&bb,&n)!=EOF) { n-=2; if(n==-1) {printf("1");return 0;} ll temp[2][2]={{aa,1},{bb,0}}; T=temp; ll temp2[2][2]={{1,1},{0,0}}; S=temp2; while(n) { if(n&1) S=S*T; T=T*T; n>>=1; } S.a[0][0]%=7; printf("%lld",S.a[0][0]); } return 0; }
2.物理和生物老师的战争
#include<iostream> #include<cstdio> using namespace std; int T,n,m; double ans; int main(){ freopen("fseq.in","r",stdin);freopen("fseq.out","w",stdout); // freopen("Cola.txt","r",stdin); scanf("%d",&T); while(T--){ ans=0; scanf("%d%d",&n,&m); if(n<m){puts("0.000000");continue;} double d=1.0/(n+1.0); printf("%.6lf\n",1.0-m*d); } }
3.化学竞赛的大奖
#include<iostream> #include<cstdio> #include<cstring> #include<vector> #define maxn 20010 #ifdef WIN32 #define PLL "%I64d" #else #define PLL "%lld" #endif using namespace std; int n,m,num,head[maxn],Num,Head[maxn]; int dfn[maxn],low[maxn],cnt,belong[maxn],gnum,st[maxn],top; long long w[maxn]; bool in[maxn]; vector<int>g[maxn]; int fa[maxn][22],dis[maxn][22],dep[maxn]; struct node{int to,pre,v;}e[400010],E[400010]; void Insert(int from,int to,int v){e[++num].to=to;e[num].v=v;e[num].pre=head[from];head[from]=num;} void Insert2(int from,int to,int v){E[++Num].to=to;E[Num].v=v;E[Num].pre=Head[from];Head[from]=Num;} void Tarjan(int u,int father){ cnt++; dfn[u]=low[u]=cnt;st[++top]=u;in[u]=1; for(int i=head[u];i;i=e[i].pre){ int v=e[i].to; if(v==father)continue; if(!dfn[v]){ Tarjan(v,u); low[u]=min(low[u],low[v]); } else if(in[v])low[u]=min(low[u],dfn[v]); } if(dfn[u]==low[u]){ gnum++; while(st[top]!=u){ int x=st[top];top--; in[x]=0; belong[x]=gnum; g[gnum].push_back(x); } in[u]=0; belong[u]=gnum; g[gnum].push_back(u); top--; } } void dfs(int now,int father){ dep[now]=dep[father]+1; fa[now][0]=father; for(int i=Head[now];i;i=E[i].pre){ int to=E[i].to; if(to==father)continue; dis[to][0]=E[i].v; dfs(to,now); } } long long lca(int a,int b){ long long res=0; if(dep[a]<dep[b])swap(a,b); for(int i=18;i>=0;i--) if(dep[fa[a][i]]>=dep[b]) res+=dis[a][i],a=fa[a][i]; if(a==b)return res; for(int i=18;i>=0;i--) if(fa[a][i]!=fa[b][i]){ res+=dis[a][i],res+=dis[b][i]; a=fa[a][i],b=fa[b][i]; } res+=dis[a][0]+dis[b][0]; return res; } int main(){ // freopen("Cola.txt","r",stdin); freopen("prize.in","r",stdin);freopen("prize.out","w",stdout); scanf("%d%d",&n,&m); int x,y,z; for(int i=1;i<=m;i++){ scanf("%d%d%d",&x,&y,&z); Insert(x,y,z); Insert(y,x,z); } for(int i=1;i<=n;i++) if(!dfn[i]) {Tarjan(i,i);} for(int con=1;con<=gnum;con++)//枚举每个国家 for(int i=0;i<g[con].size();i++){//枚举这个国家里的每个城市 int from=g[con][i]; for(int j=head[from];j;j=e[j].pre){ int to=e[j].to; if(belong[from]!=belong[to]){ Insert2(belong[to],belong[from],e[j].v); } } } dfs(1,1); for(int j=1;j<=18;j++){ for(int i=1;i<=gnum;i++){ fa[i][j]=fa[fa[i][j-1]][j-1]; dis[i][j]=dis[i][j-1]+dis[fa[i][j-1]][j-1]; } } for(int i=1;i<=gnum;i++){ long long ans=0; for(int j=1;j<=gnum;j++){ long long now=lca(i,j); ans=max(ans,now); } w[i]=ans; } for(int i=1;i<=n;i++){ printf(PLL"\n",w[belong[i]]); } }