题目是 5+ 5 5- 4+ 4 4- 3 2 1对应的分数制是100 95 90 85 80 75 70 60 <60 <60
#include <stdio.h>
main()
{
	char c1,c2;
	printf("input your score:");
	c1=getchar();
	getchar();
	c2=getchar();
	if(c1=='5')
		  {
			  if(c2=='+')	   
				printf("score=100");
			    else if(c2=='\n')
				      printf("score=90");
				    else 
				      printf("score=85");
				 
			}
    else
	    if(c1=='4')
	        {
			      if(c2=='+')
				     printf("score=80");
			    else if(c2=='\n')
				      printf("score=75");
				     else 
				      printf("score=70");
			
			}
	else  
		   if(c1=='3')
	       printf("score=60"); 
		 
	else   if(c1=='2'||c1=='1')
	          printf("score<60"); 
		   else  
			  printf("重新输入"); 
	
		
	return 0; 
}