uva213 - Message Decoding

#include <stdio.h>
#include <string.h>
int readchar();
int readint(int c);

int code[8][1<<8];
int readcodes();

int main()
{
    while(readcodes())
    {
        for(;;)
        {
            int len = readint(3);
            if(len == 0) break;
            for(;;)
            {
                int v = readint(len);
                if(v == (1 << len)-1) break;
                putchar(code[len][v]);
            }
        }
        putchar('\n');
    }
    return 0;
}

int readchar()
{
    for(;;)
    {
        int ch = getchar();
        if(ch != '\n'&&ch != '\r') return ch;
    }
}

int readint(int c)
{
    int v = 0;
    while(c--)
        v = v*2+readchar()-'0';
    return v;
}

int readcodes()
{
    memset(code, 0, sizeof(code));
    code[1][0] = readchar();
    for(int len = 2; len <= 7; len++)
    {
        for(int i = 0; i < (1<<len)-1; i++)
        {
            int ch = getchar();
            if(ch == EOF) return 0;
            if(ch == '\n'||ch == '\r') return 1;
            code[len][i] = ch;
        }
    }
    return 1;
}