题目：http://wenku.baidu.com/link?url=WgP-2UcEJy53ShbZC3gQVHZTXrHbgg14COe3HE9ybEfI82sr8nMvc-FobNBS9WwQxCEiCtb3TdETK-ZD3i3F1lMOqq3-J1cfkTrfhrbXLJe
1.转圈游戏
[快速幂]
注意：二分时记得保存值，不可重复运算；
1 #include<iostream> 2 #include<cstdio> 3 #include<queue> 4 #include<algorithm> 5 #include<cstring> 6 using namespace std; 7 int n,m,k,x; 8 int ans; 9 int PM(int a, int b, int c) 10 { 11 int ans=1; 12 a=a%c; 13 while(b>0) 14 { 15 if(b%2==1) 16 ans=(ans*a)%c; 17 b= b/2; 18 a=(a*a)%c; 19 } 20 return ans; 21 } 22 int main() 23 { 24 freopen("circle.in","r",stdin); 25 freopen("circle.out","w",stdout); 26 cin>>n>>m>>k>>x; 27 ans=PM(10,k,n); 28 cout<<(x+ans*m)%n; 29 return 0; 30 }
2.火柴排队
[归并排序][逆序对]
提示：还可以用树状数组和线段树；
1 #include<iostream> 2 #include<cstdio> 3 #include<queue> 4 #include<algorithm> 5 #include<cstring> 6 using namespace std; 7 int ans; 8 struct poin{ 9 int num; 10 int s; 11 }q[100005]; 12 poin w[100005]; 13 int com(const poin &a,const poin &b) 14 { 15 if(a.s<b.s)return 1; 16 return 0; 17 } 18 int n; 19 int a[100005],r[100005]; 20 void mergesort(int s,int t) 21 { 22 if(s==t)return ; 23 int m=(s+t)>>1; 24 mergesort(s,m); 25 mergesort(m+1,t); 26 int i=s; 27 int j=m+1; 28 int k=s; 29 while(i<=m&&j<=t) 30 { 31 if(a[i]<=a[j]) 32 { 33 r[k++]=a[i++]; 34 } 35 else 36 { 37 ans=(ans+m-i+1)%99999997; 38 r[k++]=a[j++]; 39 } 40 } 41 while(i<=m) 42 r[k++]=a[i++]; 43 while(j<=t) 44 r[k++]=a[j++]; 45 for(int i=s;i<=t;i++) 46 a[i]=r[i]; 47 } 48 int main() 49 { 50 freopen("match.in","r",stdin); 51 freopen("match.out","w",stdout); 52 cin>>n; 53 for(int i=1;i<=n;i++) 54 { 55 scanf("%d",&q[i].s); 56 q[i].num=i; 57 } 58 for(int j=1;j<=n;j++) 59 { 60 scanf("%d",&w[j].s); 61 w[j].num=j; 62 } 63 sort(q+1,q+1+n,com); 64 sort(w+1,w+1+n,com); 65 for(int i=1;i<=n;i++) 66 a[w[i].num]=q[i].num; 67 mergesort(1,n); 68 cout<<ans; 69 return 0; 70 }
3.货车运输
[不会][60分][并查集]
1 #include<cstdio> 2 #include<iostream> 3 #include<algorithm> 4 using namespace std; 5 int father[10001]; 6 int n,q,tot,m; 7 struct xx{ 8 int x,y,w; 9 }bian[50005]; 10 int find(int x)// 11 { 12 if(father[x]!=x) father[x]=find(father[x]); 13 return father[x]; 14 } 15 void unionn(int a,int b)// 16 { 17 int fa=find(a); 18 int fb=find(b); 19 if(fa!=fb) father[fa]=fb; 20 } 21 bool cmp(const xx a,const xx b) 22 { 23 return b.w<a.w; 24 } 25 int main() 26 { 27 freopen("truck.in","r",stdin); 28 freopen("truck.out","w",stdout); 29 cin>>n>>m; 30 for(int i=1;i<=m;i++) 31 { 32 int x,y,z; 33 scanf("%d %d %d",&x,&y,&z); 34 bian[i].x=x,bian[i].y=y,bian[i].w=z; 35 } 36 sort(bian+1,bian+m+1,cmp); 37 cin>>q; 38 for(int i=1;i<=q;i++) 39 {int x,y,minn=1e6,k=1; 40 for(int i=1;i<=n;i++)father[i]=i; 41 scanf("%d %d",&x,&y); 42 for(int i=1;i<=m;i++) 43 { 44 if(find(x)==find(y)){ 45 printf("%d ",minn); 46 break; 47 } 48 else if(find(bian[i].x)!=find(bian[i].y)) 49 { 50 unionn(bian[i].x,bian[i].y); 51 if(bian[i].w<minn) 52 minn=bian[i].w; 53 } 54 } 55 if(find(x)!=find(y)) printf("-1 "); 56 } 57 return 0; 58 }