HDU 1316 How Many Fibs?

 

How Many Fibs?

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 1212    Accepted Submission(s): 501


[align=left]Problem Description[/align]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].
 
[align=left]Input[/align]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.
 
[align=left]Output[/align]For each test case output on a single line the number of Fibonacci numbers fi with a <= fi <= b.
 
[align=left]Sample Input[/align]

10 100
1234567890 9876543210
0 0 
[align=left]Sample Output[/align]

5
4 
[align=left]Source[/align]University of Ulm Local Contest 2000  
[align=left]Recommend[/align]Eddy 听到KID既大数题目题目推荐！我都用STL写左一个有加法重载既大数类。不过令我WA多次既问题竟然系读错题目{=     =b}，f2 = 1，结果WA多次，真系…………下面直接贴代码： 

4281094

2011-07-28 20:00:08

Accepted

1316

156MS

416K

2614 B

C++

10SGetEternal{（。）（。）}!

#include <iostream>
#include <string>
#include <vector>
using namespace std;
#define MAXI 486

class Bnum
{
public :

vector<int> n;
int l;

Bnum(string str = "0")
{
int i;

l = str.length();
n.resize(l);
for (i = 0; i < l; i++)
n[i] = str[l - i - 1] - 48;
}

Bnum & operator = (Bnum &o)
{
l = o.l;
n = o.n;

return o;
}

friend Bnum operator + (Bnum a, Bnum b)
{
Bnum c;
int i, len = a.l > b.l? a.l: b.l;

c.l = len + 1;
c.n.resize(c.l);
a.n.resize(c.l);
b.n.resize(c.l);
for (c.n[len] = i = 0; i < len; i++)
{
c.n[i] += a.n[i] + b.n[i];
c.n[i + 1] = c.n[i] / 10;
c.n[i] %= 10;
}
if (!c.n[c.l - 1]) c.n.resize(--c.l);

return c;
}

friend bool operator < (Bnum a, Bnum b)
{
int i;

if (a.l == b.l)
{
for (i = a.l - 1; i >= 0; i--)
if (a.n[i] < b.n[i]) return 1;
else if (a.n[i] > b.n[i]) return 0;
return 0;
}
else return a.l < b.l;
}

friend bool operator > (Bnum a, Bnum b)
{
int i;

if (a.l == b.l)
{
for (i = a.l - 1; i >= 0; i--)
if (a.n[i] > b.n[i]) return 1;
else if (a.n[i] < b.n[i]) return 0;
return 0;
}
else return a.l > b.l;
}

friend bool operator == (Bnum a, Bnum b)
{
int i;

if (a.l == b.l)
{
for (i = a.l - 1; i >= 0; i--)
if (a.n[i] != b.n[i]) return 0;
return 1;
}
else return 0;
}

friend bool operator <= (Bnum a, Bnum b) { return a == b || a < b; }
friend bool operator >= (Bnum a, Bnum b) { return a == b || a > b; }

friend ostream & operator << (ostream & output, Bnum &o)
{
int i;

for (i = 0; i < o.l; i++)
output << o.n[o.l - i - 1];

return output;
}

friend istream & operator >> (istream & input, Bnum &o)
{
string buf;

input >> buf;
o = Bnum(buf);

return input;
}

}fin[MAXI];

void init()
{
int i;

fin[1] = Bnum("1");
fin[2] = Bnum("2");
for (i = 3;; i++)
if (fin[i - 1].l >= 102) break;
else fin[i] = fin[i - 1] + fin[i - 2];
}

int main()
{
int i, sum;
Bnum a, b;

init();
while (cin >> a >> b)
{
if (a == Bnum("0") && b == Bnum("0")) break;
for (sum = 0, i = 1; i < MAXI; i++)
if (fin[i] > b) break;
else if (a <= fin[i] && fin[i] <= b)
sum++;
cout << sum << endl;
}

return 0;
}

下面贴上K神关于呢个题目既博文！！！
http://972169909-qq-com.iteye.com/blog/1133478