问题链接:Fibonacci Freeze
The Fibonacci numbers (0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, ...) are defined by the recurrence:
F0 = 0
F1 = 1
Fi = Fi−1 + Fi−2 for all i ≥ 2
Write a program to calculate the Fibonacci Numbers.
Input
The input to your program would be a sequence of numbers smaller or equal than 5000, each on a separate line, specifying which Fibonacci number to calculate.
Output
Your program should output the Fibonacci number for each input value, one per line.
Sample Input
5
7
11
Sample Output
The Fibonacci number for 5 is 5
The Fibonacci number for 7 is 13
The Fibonacci number for 11 is 89
程序说明:
用二维数组来表示大数,并且采用万进制,高位在每一行的右边(低位在左边)。
C++:
/* UVA495 Fibonacci Freeze */
#include <bits/stdc++.h>
using namespace std;
const int N = 5000;
const int N2 = 300;
const int BASE = 1e4;
int fib[N+ 1][N2 + 1];
void maketable()
{
memset(fib, 0, sizeof(fib));
fib[0][0] = 0;
fib[1][0] = 1;
for ( int i = 2 ; i <= N ; i++ ) {
for ( int j = 0 ; j <= N2 ; j++ )
fib[i][j] = fib[i-2][j] + fib[i-1][j];
for ( int j = 0 ; j <= N2 ; j++ ) {
fib[i][j+1] += fib[i][j] / BASE;
fib[i][j] %= BASE;
}
}
}
int main()
{
maketable();
int n;
while(~scanf("%d", &n)) {
int i = N2;
while ( i >= 1 && !fib[n][i] )
i --;
printf("The Fibonacci number for %d is ", n);
printf("%d", fib[n][i--]);
while ( i >= 0 )
printf("%04d", fib[n][i--]);
printf("\n");
}
return 0;
}