LA 6449 IQ Test

【题目】

给出一个长度为n的数组(8<n<12)，告诉你规律

 (1<=d<=3)要求d尽量小

现在求第n+1项

【题解】

水题

不知道怎么求a1~ad?用克拉默法则

【代码】

RunID

User

Problem

Result

Memory

Time

Language

Length

Submit Time

2548731

zhyfzy

F

Accepted

0 KB

6 ms

C++ 4.5.3

1534 B

2014-07-31 15:10:56

#include<cstdio>#include<cstring>#include<cmath>#include<iostream>#include<algorithm>#define eps 0.000001using namespace std;int i,j,k,n,m,T,ans,big;bool flag;double x,y,z,a[100];bool equ(double x,double y){if (fabs(x-y)<eps) return true;return false;}int main(){scanf("%d",&T);while (T--){scanf("%d",&n);for (i=1;i<=n;i++)scanf("%lf",&a[i]);if (a[1]!=0){x=a[2]/a[1];flag=false;for (i=3;i<=n;i++){if (!equ(a[i],x*a[i-1])) {flag=true; break; }}if (!flag){printf("%.0lf\n",a[n]*x);continue;}}if (a[1]*a[3]-a[2]*a[2]!=0){flag=false;x=(a[3]*a[3]-a[2]*a[4])/(a[1]*a[3]-a[2]*a[2]);y=(a[1]*a[4]-a[2]*a[3])/(a[1]*a[3]-a[2]*a[2]);for (i=5;i<=n;i++){if (!equ(a[i],x*a[i-2]+y*a[i-1])){flag=true;break;}}if (!flag){printf("%.0lf\n",a[n-1]*x+a[n]*y);continue;}}flag=false;x=(a[4]*(a[3]*a[5]-a[4]*a[4])-a[2]*(a[5]*a[5]-a[6]*a[4])+a[3]*(a[5]*a[4]-a[6]*a[3]))/(a[1]*(a[3]*a[5]-a[4]*a[4])-a[2]*(a[2]*a[5]-a[3]*a[4])+a[3]*(a[2]*a[4]-a[3]*a[3]));y=(a[1]*(a[5]*a[5]-a[4]*a[6])-a[4]*(a[2]*a[5]-a[3]*a[4])+a[3]*(a[2]*a[6]-a[3]*a[5]))/(a[1]*(a[3]*a[5]-a[4]*a[4])-a[2]*(a[2]*a[5]-a[3]*a[4])+a[3]*(a[2]*a[4]-a[3]*a[3]));z=(a[1]*(a[3]*a[6]-a[4]*a[5])-a[2]*(a[2]*a[6]-a[3]*a[5])+a[4]*(a[2]*a[4]-a[3]*a[3]))/(a[1]*(a[3]*a[5]-a[4]*a[4])-a[2]*(a[2]*a[5]-a[3]*a[4])+a[3]*(a[2]*a[4]-a[3]*a[3]));printf("%.0lf\n",a[n-2]*x+a[n-1]*y+a[n]*z); } }