题解 | #进制转换#

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#define len 10001
#define maxint 1<<31-1

int chartoint(char c){
    int a = c-'0';
    if(a>=0&&a<=9){
        return a;
    }
    return -1;
}

char inttochar(char c){
    return c+'0';
}

void newdiv(char str[],int x){
    int remain = 0;
    char temp[len];
    for(int i = 0;i<len;i++){
        temp[i] = '\0';
    }
    for(int i = 0;i<strlen(str)-1;i++){
        int a = chartoint(str[i]);
        int sum = a+remain*10;
        temp[i] = inttochar(sum/x);
        remain = sum%x;
    }
    int i = 0;
    while(temp[i]=='0'){
        i++;
    }

    int j;
    for(j = 0;temp[i+j]!='\0';j++){
        str[j] = temp[i+j];
    }
    str[j] = '\n';
    str[j+1] = '\0';

    if(temp[i]=='\0'){
        str[0] = '0';
        str[1] = '\0';
    }
}

int newmod(char str[],int x){
    char c = str[strlen(str)-2];
    int a = chartoint(c);
    return a%x;
}

int t;
int stack[len];

void push(int x){
    stack[t++] = x;
}

int pop(){
    if(t==0){
        return 1<<31;
    }
    return stack[--t];
}

int main(){
    char str[len];
    while(fgets(str,sizeof(str),stdin)){
        t = 0;
//        newdiv(str,2);
//        printf("%s",str);
        while(strcmp(str,"0")!=0){
            //printf("%s",str);
            int a = newmod(str,2);
            push(a);
            newdiv(str,2);
        }
        while(t!=0){
            printf("%d",pop());
        }
        printf("\n");
    }
}