I - Triangle
HDU - 5914
Mr. Frog has n sticks, whose lengths are 1,2, 3⋯⋯n respectively. Wallice is a bad man, so he does not want Mr. Frog to form a triangle with three of the sticks here. He decides to steal some sticks! Output the minimal number of sticks he should steal so that Mr. Frog cannot form a triangle with
any three of the remaining sticks.
Input
The first line contains only one integer T (T≤20T≤20), which indicates the number of test cases.
For each test case, there is only one line describing the given integer n (1≤n≤201≤n≤20).
Output
For each test case, output one line “Case #x: y”, where x is the case number (starting from 1), y is the minimal number of sticks Wallice should steal.
Sample Input
3
4
5
6
Sample Output
Case #1: 1
Case #2: 1
Case #3: 2
题意：从1到n的序列，去掉一些数，使剩下的数不能构成三角形。
解法：斐波纳挈数列，三角形两边之和不能大于第三边，首先1和2保留，还能剩下的数等于它前两个剩下的数之和
代码：
#include<iostream>
using namespace std;
int fib(int k)
{
int a=1,b=2;
int temp,ans=1;
while(b<=k){
temp=a;
a=b;
b+=temp;
ans++;
}
return k-ans;
}
int main()
{
int n;
cin>>n;
for(int i=0;i<n;i++){
int k;
cin>>k;
cout<<"Case #"<<i+1<<": "<<fib(k)<<endl;
}
return 0;
}
