杭电_ACM_Hat's Fibonacci

100

4203968145672990846840663646

Note:
No generated Fibonacci number in excess of 2005 digits will be in the test data, ie. F(20) = 66526 has 5 digits.

#include <stdio.h>
#include <string.h>
int f[10000][505] = {0};
int main()
{
int n, carry, sum, i, j, length;
//f[number][0] is the length of the number
f[1][0] = 1;
f[1][1] = 1;
f[2][0] = 1;
f[2][1] = 1;
f[3][0] = 1;
f[3][1] = 1;
f[4][0] = 1;
f[4][1] = 1;
while (scanf("%d", &n) != EOF)
{
if (n < 5)
{
puts("1");
continue;
}
for (i = 5; i <= n; i++)
{
f[i][0] = f[i - 1][0];
carry = 0;
//splite the number by four
for (j = 1; j <= f[i][0]; j++)
{
sum = f[i -1][j] + f[i - 2][j] + f[i - 3][j] + f[i - 4][j] + carry;
f[i][j] = sum % 10000;
carry = sum / 10000;
}
//if the carry is not zero, then the length must plus one
if (carry != 0)
{
f[i][0]++;
f[i][j] = carry;
}
}
//formatted printing
length = f
[0];
printf("%d", f
[length]);
for (i = length - 1; i >= 1; i--)
printf("%04d",f
[i]);
printf("\n");
}
return 0;
}