CSP-S 模拟测试94题解

T1 yuuustu：

可以对两边取对数，然后就转化为两个double的比较，时间复杂度$O(n)$

然后我就用神奇0.4骗分水过

 

 1 #include<bits/stdc++.h>
 2 using namespace std;
 3 const int N=1e6+10;
 4 struct BigInt{
 5     int a[100005];
 6     BigInt(){memset(a,0,sizeof(a));a[0]=a[1]=1;}
 7     BigInt friend operator * (BigInt x,int y){
 8         int len=x.a[0],las=0;
 9         for(register int i=1;i<=len;++i){
10             x.a[i]=x.a[i]*y+las;
11             las=x.a[i]/10;
12             x.a[i]%=10;
13             if(i==len&&las) ++len;
14         }
15         return x.a[0]=len,x;
16     }
17     void print(){
18         for(int i=a[0];i>=1;--i) cout<<a[i];
19     }
20 };
21 inline bool chk(BigInt a,BigInt b){
22     for(int i=0;i<=a.a[0];++i) if(a.a[i]!=b.a[i]) return 0;
23     return 1;
24 }
25 inline bool cmp(BigInt a,BigInt b){//x^y   y!
26     if(a.a[0]==b.a[0]) if(chk(a,b)) return 1;
27     if(a.a[0]^b.a[0]) return a.a[0]<b.a[0];
28     else{
29         for(register int i=a.a[0];i>=1;--i){
30             if(a.a[i]==b.a[i]) continue;
31             if(a.a[i]>b.a[i]) return 0;
32             else if(a.a[i]<b.a[i]) return 1;
33         }
34     }
35 }
36 void work_1(int x,int y){
37     if(x>y*0.4) puts("No");
38     else puts("Yes");
39 }
40 int main(){
41     freopen("yuuutsu.in","r",stdin);
42     freopen("yuuutsu.out","w",stdout);
43     int T;
44     scanf("%d",&T);register int x,y;
45     while(T--){
46         scanf("%d%d",&x,&y);
47         if(x>1000||y>1000){work_1(x,y);continue;}
48         BigInt Fir,Sec;
49         Fir.a[0]=Fir.a[1]=1;
50         Sec.a[0]=Sec.a[1]=1;
51         for(register int i=1;i<=y;++i) Fir=Fir*x;
52         for(register int i=1;i<=y;++i) Sec=Sec*i;
53         //Fir.print();puts("");Sec.print();
54         if(cmp(Fir,Sec)) puts("Yes");
55         else puts("No");
56     }
57     fclose(stdin);
58     fclose(stdout);
59     return 0;
60 }

yuuutsu