【HDOJ】2051 Bitset

水题。

#include <stdio.h>
#include <string.h>

#define MAXNUM 32

char bin[MAXNUM];

void itob(int a, char bin[]) {
    int tmp = a, i=0;
    char ch;

    memset(bin, 0, sizeof(bin));

    do {
        ch = tmp&1;
        bin[i++] = ch + '0';
        tmp = tmp >> 1;
    } while (tmp > 0);

    // bin[i] = '\0';
}

int main() {
    int n;
    int i;

    while (scanf("%d", &n) != EOF) {
        itob(n, bin);
        for (i=strlen(bin)-1; i>=0; --i)
            printf("%c", bin[i]);
        printf("\n");
    }

    return 0;
}