题解 | #数制转换# c纯模拟

#include <stdio.h>

int main() {
    int a, b;
    char n[100];
    char charac[16]={"0123456789ABCDEF"};
    while (scanf("%d %s %d", &a,n, &b) != EOF) { // 注意 while 处理多个 case
       char ans[100];
       long long num=0;
       for(int i=0;n[i]!='\0';i++)
       {
            if(n[i]<='z'&&n[i]>='a')
            num=num*a+n[i]-'a'+10;
            else if(n[i]<='Z'&&n[i]>='A')
            num=num*a+n[i]-'A'+10;
            else
            num=num*a+n[i]-'0';
       }
       //printf("num=%d\n",num);
       int i=0;
       while(num)
       {
            ans[i++]=charac[num%b];
            num=num/b;
       }
       //printf("i=%d\n",i);
       i--;
       for(;i>=0;i--)
       printf("%c",ans[i]);
       printf("\n");
    }
    return 0;
}