#include<stdio.h>
#include<math.h>
//打印任意整数 
void printDigit(int count){
	if(count>0){
		if(count>10){
			printDigit(count/10);
		}
		//else
		{
			printf("%d",count%10);
		}
	}else{
		count=0-count;
		printf("-");
		printDigit(count);
	} 
	
} 

//自已实现round函数
float  myRound(float count,int num){
	double f=pow(10.0,double(num));
	double t;
	double x=count*f;

	if(x>=0){
		t=ceil(x);
		if((t-x)>0.500000000001){
			t-=1.0;
		}
	}
	///只处理正的
	else{
		t=ceil(-x);
		if((t+x)>0.500000000001){
			t-=1.0;
		}
		t=-t;
	} 
	x=t/f;
	
	return float(t);
}

//找印任意实数   round实现了四舍五入 
void printDigit2(float count,int num){
	int mode=1;
	if(count>0){
		for(int i=0;i<num;i++){
			count=count*10;
			mode=mode*10;
		}
		
		count=myRound(count,0);
		 
		
		int num1=count/mode;
		int num2=(int)(count)%mode;
		printDigit(num1);
		printf(".");
		printDigit(num2); 
	}else if(count<0){
		printf("-");
		printDigit2(0.0-count,num);
	}

} 

int main(){
	printDigit2(-203.4567,4);
}