Problem B: How many Fibs?
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].
Input Specification
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<=10100.
The numbers a and b are given with no superfluous leading zeros.
Output Specification
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
题意:给定两个数,求两个数之间的斐波那契数列。
思路:高精度解决。。
代码:
#include <stdio.h> #include <string.h> #define max(a,b) (a)>(b)?(a):(b) #define min(a,b) (a)<(b)?(a):(b) const int N = 2222; const int MAXBIGN = 305; struct bign { int s[MAXBIGN]; int len; bign() { len = 1; memset(s, 0, sizeof(s)); } bign operator = (const char *number) { len = strlen(number); for (int i = 0; i < len; i++) s[len - i - 1] = number[i] - '0'; return *this; } bign operator = (const int num) { char number[N]; sprintf(number, "%d", num); *this = number; return *this; } bign (int number) {*this = number;} bign (const char* number) {*this = number;} bign operator + (const bign &c){ bign sum; int t = 0; sum.len = max(this->len, c.len); for (int i = 0; i < sum.len; i++) { if (i < this->len) t += this->s[i]; if (i < c.len) t += c.s[i]; sum.s[i] = t % 10; t /= 10; } while (t) { sum.s[sum.len++] = t % 10; t /= 10; } return sum; } bign operator - (const bign &c) { bign ans; ans.len = max(this->len, c.len); int i; for (i = 0; i < c.len; i++) { if (this->s[i] < c.s[i]) { this->s[i] += 10; this->s[i + 1]--; } ans.s[i] = this->s[i] - c.s[i]; } for (; i < this->len; i++) { if (this->s[i] < 0) { this->s[i] += 10; this->s[i + 1]--; } ans.s[i] = this->s[i]; } while (ans.s[ans.len - 1] == 0) { ans.len--; } if (ans.len == 0) ans.len = 1; return ans; } void put() { if (len == 1 && s[0] == 0) { printf("0"); } else { for (int i = len - 1; i >= 0; i--) printf("%d", s[i]); } } bool operator < (const bign& b) const { if (len != b.len) return len < b.len; for (int i = len - 1; i >= 0; i--) if (s[i] != b.s[i]) return s[i] < b.s[i]; return false; } bool operator > (const bign& b) const { return b < *this; } bool operator <= (const bign& b) const { return !(b < *this); } bool operator >= (const bign& b) const { return !(*this < b); } bool operator != (const bign& b) const { return b < *this || *this < b;} bool operator == (const bign& b) const { return !(b != *this); } }; bign f[N]; void init() { f[0] = "1"; f[1] = "2"; for (int i = 2; i < N; i ++) f[i] = f[i - 1] + f[i - 2]; } int i, count; char a[105], b[105]; int main () { init(); while (~scanf("%s%s", a, b)) { count = 0; if (!strcmp(a, "0") && !strcmp(b, "0")) break; bign n1 = a, n2 = b; for (i = 0; i < N; i ++) if (f[i] >= n1) break; for (;i < N; i ++) { if (f[i] > n2) break; count ++; } printf("%d\n", count); } return 0; }