Hdu1250_hat's Fibonacci [large number] [water question]

Hat's Fibonacci

Time Limit: 2000/1000 MS (Java/others) memory limit: 65536/32768 K (Java/others) total submission (s): 7854 accepted submission (s): 2551
Problem description
A Fibonacci sequence is calculated by adding the previous two members the sequence, with the first two members being both 1.
F (1) = 1, F (2) = 1, F (3) = 1, F (4) = 1, F (n> 4) = f (n-1) + f (n-2) + f (n-3) + f (n-4)
Your task is to take a number as input, and print that maid number.

Input
Each line will contain an integers. process to end of file.
 
Output
For each case, output the result in a line.
 
Sample Input
100
 
Sample output
4203968145672990846840663646

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

Wearing a hat

#include<stdio.h>#include<string.h>int f1[2050],f2[2050],f3[2050],f4[2050],f5[2050];int main(){    int N;    while(~scanf("%d",&N))    {        if(N==1)            printf("1\n");        else if(N==2)            printf("1\n");        else if(N==3)            printf("1\n");        else if(N==4)            printf("1\n");        else        {            memset(f1,0,sizeof(f1));            memset(f2,0,sizeof(f2));            memset(f3,0,sizeof(f3));            memset(f4,0,sizeof(f4));            memset(f5,0,sizeof(f5));            f1[0] = f2[0] = f3[0] = f4[0] = 1;            for(int i = 5; i<= N; i++)            {                for(int j = 0; j <= 2010; j++)                {                    f5[j] = f1[j] + f2[j] + f3[j] + f4[j];                    if(f5[j] >= 10)                    {                        f1[j+1] += (f5[j]/10);                        f5[j] = (f5[j]%10);                    }                    f1[j] = f2[j];                    f2[j] = f3[j];                    f3[j] = f4[j];                    f4[j] = f5[j];                }            }            int j;            for(j = 2010; j >= 0; j--)                if(f5[j]!=0)                    break;            for(int i = j; i >= 0; i--)                printf("%d",f5[i]);            printf("\n");        }    }    return 0;}

Hdu1250_hat's Fibonacci [large number] [water question]