How Many Fibs?
How Many Fibs?
Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 5158 Accepted Submission(s):
2007
Problem Description
Recall the definition of the Fibonacci numbers:
f1 := 1
f2 := 2
fn := fn-1 + fn-2 (n >= 3)
Given two numbers a and b, calculate how many Fibonacci numbers are in the range [a, b].
f1 := 1
f2 := 2
fn := fn-1 + fn-2 (n >= 3)
Given two numbers a and b, calculate how many Fibonacci numbers are in the range [a, b].
Input
The input contains several test cases. Each test case
consists of two non-negative integer numbers a and b. Input is terminated by a =
b = 0. Otherwise, a <= b <= 10^100. The numbers a and b are given with no
superfluous leading zeros.
Output
For each test case output on a single line the number
of Fibonacci numbers fi with a <= fi <= b.
Sample Input
10 100
1234567890 9876543210
0 0
Sample Output
5
4
思路很简单,但做得时候思维不严谨小的地方错了好多,一直在debug
#include <iostream> #include <cstdio> #include <cstring> using namespace std; #define len 10 int _cmp(char *a,char *b) { int i=0,j,count=0; if(strlen(a)<strlen(b)) return 1; else if(strlen(a)>strlen(b)) return -1; else { char x[110]; int j=0,len1=strlen(a); for(i=len1-1;i>=0;i--) /*倒置,全部都是高位在右,从右往左比较*/ x[j++]=a[i]; x[j]='\0'; i=len1-1; while(i>=0) { if(b[i]>x[i]) return 1; else if(b[i]==x[i]) i--; else { return -1; } } return 0; } } char f[600][110]; int main() { memset(f,'0',sizeof(f)); int c,i,j,count,n; char a[101],b[101]; f[1][0]='1'; f[2][0]='2'; for(i=3;i<600;i++) { c=0; for(j=0;j<110;j++) { f[i][j]=(f[i-2][j]+f[i-1][j]+c-2*'0')%len+'0'; c=(f[i-2][j]+f[i-1][j]+c-2*'0')/len; } } for(i=1;i<600;i++) /*变成字符串方便实用strlen()*/ for(j=109;j>=0;j--) if(f[i][j]!='0') { f[i][j+1]='\0'; break; } while(cin>>a>>b) { if(a[0]=='0'&&b[0]=='0') break; count=0; j=0; for(i=1;i<=599;i++) { if(_cmp(a,f[i])>=0&&_cmp(b,f[i])<=0) count++; if(_cmp(b,f[i])>=0) break; } cout<<count<<endl; } }