參考了

根據參考1有

#include <cstdio>
#include <cstring>
#define MAXN 4000

int main(){ 
    int to[MAXN];
    int from[MAXN]; 
    char str[1000];
    while(scanf("%s",str) !=EOF ){ 
        int len = (int)  strlen(str);  
        for (int i = 0; i < len; ++i) { 
            from[i] = str[i] - '0'; 
        } 

        int toLen = 0;
        while(true){ 
            int i = 0; 
            while(i<len&&from[i] == 0) i++; 
            if(i==len) break; 
            int remainder = 0;
            for (; i < len; i++) { 
                int temp = remainder*10+from[i]; 
                from[i] = temp/2;
                remainder = temp%2;
            } 
            to[toLen++] = remainder;

        }  

        if(toLen == 0){ 
            printf("0\n");  
        }else{ 
            int newLen = 1;
            memset(from,0,sizeof(from) ); 
            for (int i = 0; i < toLen; ++i) { 
                for (int j = 0;  j< newLen; ++j) { 
                    from[j] *= 2; 
                } 
                if(to[i]) from[0]+=to[i];
                int c = 0;
                for (int j = 0; j < newLen; ++j) { 
                    from[j] += c;
                    if(from[j] >=10){ 
                        c = from[j]/10;
                        from[j] %=10; 
                    }else{ 
                        c = 0; 
                    }    
                } 

                while(c){ 
                    from[newLen++] = c%10;
                    c /=10; 
                }  
            } 
            for (int i = newLen-1; i >=0; i--) { 
                printf("%c",from[i]+'0');  
            } 
            printf("\n"); 
        }    
    }  
}  
 

根據參考2有：

#include <cstdio>
#include <cstring>
#define MAXN 4000

int main(){ 
    int to[MAXN];
    int from[MAXN]; 
    char str[1000];
    while(scanf("%s",str) !=EOF ){ 
        int len = (int)  strlen(str);  
        for (int i = 0; i < len; ++i) { 
            from[i] = str[i] - '0'; 
        } 

        int toLen = 0;
        while(true){ 
            int i = 0; 
            while(i<len&&from[i] == 0) i++; 
            if(i==len) break; 
            int remainder = 0;
            for (; i < len; i++) { 
                int temp = remainder*10+from[i]; 
                from[i] = temp/2;
                remainder = temp%2;
            } 
            to[toLen++] = remainder;

        }  

        if(toLen == 0){ 
            printf("0\n");  
        }else{
            int newLen = 0;
            while(true){ 
               int i = 0;  
               while(i<toLen && to[i] == 0) i++;
               if(i == toLen) break;  
               int remainder = 0;
               for(;i<toLen;i++){ 
                  int temp  = remainder*2 + to[i];  
                  to[i] = temp/10;
                  remainder = temp%10;
               }  
               from[newLen++] = remainder;
            }  
            for (int i = newLen-1; i >=0; --i) { 
                printf("%c",from[i]+'0');  
            } 
            printf("\n"); 
        } 
    }  
}