#include <stdio.h>
/*
printf中%d的妙用 
%5d:宽度5，右对齐，空格补 
%05d(%.5d)：宽度5，右对齐，0补 
%-5d：宽度5，左对齐，空格补→不能写%-.5d 

printf中%c,%s的妙用
%.2s：输出前两位 
*/
int main(){
	double a=2,b=4;
	a/=3;
	b/=7;
	printf("double:\na = %04.2f%%, b = %55.50f%%\n",a,b);
	printf("a = %07f, b = %08f\n",a,b);
	int c=345;
	printf("int:\nc = %.6d\n",c);
	printf("c = %05d\n",c);
	printf("c = %-5d\n",c);
	double f=123456;
	printf("e:\nf = %10.2e\n",f);
	char d[]="canyoukissmyass";
	printf("string:\n%.2s\n",d);
	return 0;
}