uva 10183 - How Many Fibs?(斐波那契数）

#include <stdio.h>
#include <string.h>
const int N = 105;

struct bign {
int len, sex;
int s
;

bign() {
this -> len = 1;
this -> sex = 0;
memset(s, 0, sizeof(s));
}

bign operator = (const char *number) {
int begin = 0;
len = 0;
sex = 1;
if (number[begin] == '-') {
sex = -1;
begin++;
}
else if (number[begin] == '+')
begin++;

for (int j = begin; number[j]; j++)
s[len++] = number[j] - '0';
}

bign operator = (int number) {
char string
;
sprintf(string, "%d", number);
*this = string;
return *this;
}

bign (int number) {*this = number;}
bign (const char* number) {*this = number;}

bool operator < (const bign& b) const {
if (len != b.len)
return len < b.len;
for (int i = 0; i < len; 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 change(bign cur) {
bign now;
now = cur;
for (int i = 0; i < cur.len; i++)
now.s[i] = cur.s[cur.len - i - 1];
return now;
}

bign operator + (const bign &cur){
bign sum, a, b;
sum.len = 0;
a = a.change(*this);
b = b.change(cur);

for (int i = 0, g = 0; g || i < a.len || i < b.len; i++){
int x = g;
if (i < a.len) x += a.s[i];
if (i < b.len) x += b.s[i];
sum.s[sum.len++] = x % 10;
g = x / 10;
}
return sum.change(sum);
}
};

int l, r;
char a
, b
;
bign f, s;
bign begin, end;

void solve() {
int flag = 1;
for (int i = 1; ; i++) {
if (i % 2) {
s = f + s;
if (s >= begin && flag) {
l = i;
flag = 0;
}
if (s > end) {
r = i;
return ;
}
} else {
f = f + s;
if (f >= begin && flag) {
l = i;
flag = 0;
}
if (f > end) {
r = i;
return ;
}
}
}
}
int main () {
while (scanf("%s%s", a, b) == 2) {
if (a[0] == '0' && b[0] == '0') break;
begin = a, end = b;
f = 1, s = 0;
solve();
printf("%d\n", r - l);
}
return 0;
}