1 #include <cstdio> 2 #include <cstring> 3 #include <iostream> 4 using namespace std; 5 char s[105]; 6 int main(){ 7 bool is_native; 8 int len, point, endline; 9 while(~scanf("%[^ ]",s)){ 10 getchar();//吃回车 11 if(s[0] == '-') is_native = true;//判断负数 12 else is_native = false; 13 point = len = strlen(s);//当没有小数点时，len处为小数点 14 for(int i = 0; s[i]; ++i)//找小数点 15 if(s[i] == '.'){ 16 point = i; 17 break; 18 } 19 endline = point;//.999 20 if(point-1 >= 0 && s[point-1] >= '0' && s[point-1] <= '9')//0.999 21 endline = point-1; 22 for(int i = 0; i < point; ++i)//00000123 23 if(s[i] > '0' && s[i] <= '9'){ 24 endline = i; 25 break; 26 } 27 s[point] = '.';//len处可能没有. 28 for(int i = point+1; i <= point+3; ++i)//处理小数点后三位 29 s[i] = s[i]?:'0'; 30 if(s[point+3] > '4') ++s[point+2];//小数点后第二位的进位 31 int up = s[point+3] = 0; 32 for(int i = point+2; i >= endline; --i){//依次进位 33 if(i == point) continue; 34 s[i] += up; 35 up = (s[i]-'0')/10; 36 s[i] = (s[i]-'0')%10 + '0'; 37 } 38 bool is_all_zero = true;//0000000.0之类的 39 for(int i = point-1; i >= endline; --i) 40 if(s[i] != '0') is_all_zero = false; 41 if(up) is_all_zero = false;//0.999 42 int num = (point+2)%3;//找出在那加入, 43 if(is_native) putchar('('); 44 if(up){ 45 printf("%d",up); 46 if(s[0] != '.' && (endline+2)%3 == num) 47 putchar(','); 48 } 49 int i; 50 if(is_all_zero) { putchar('0'); i = point; }//前面都是零输出一个零，并从小数点处开始继续输出 51 else i = endline;//否则从开头开始 52 for(; i < point+3; ++i){ 53 putchar(s[i]); 54 if(i < point-1 && i%3 == num) 55 putchar(','); 56 } 57 if(is_native) putchar(')'); 58 putchar(' '); 59 memset(s,0,sizeof(s));//清空数组，防止干扰 60 } 61 return 0; 62 }