ACM之路刚刚开始

其实我完全没甚么废话好说的，只是希望养成一个总结的好习惯。让自己以后思路更加清晰。

比如说下面的一道来自杭电的ACM-Steps的一道比较简单的题目，但是为甚么多次提交都是错误，可是不管怎么调试都是对的，其实是题目没有好好看。

GPA

Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)

Total Submission(s): 3580 Accepted Submission(s): 1466

Problem Description

Each course grade is one of the following five letters: A, B, C, D, and F. (Note that there is no grade E.) The grade A indicates superior achievement , whereas F stands for failure. In order to calculate the GPA, the letter grades A, B, C, D, and F are assigned the following grade points, respectively: 4, 3, 2, 1, and 0.

 

Input

The input file will contain data for one or more test cases, one test case per line. On each line there will be one or more upper case letters, separated by blank spaces.

 

Output

Each line of input will result in exactly one line of output. If all upper case letters on a particular line of input came from the set {A, B, C, D, F} then the output will consist of the GPA, displayed with a precision of two decimal places. Otherwise, the message "Unknown letter grade in input" will be printed.

 

Sample Input

A B C D F
B F F C C A
D C E F

 

Sample Output

2.00
1.83
Unknown letter grade in input

 

Author

2006Rocky Mountain Warmup

 

Source

HDU “Valentines Day” Open Programming Contest 2009-02-14

 

Recommend

lcy

这道题其实真的没有什么难度，但是输出格式还是要注意，尤其对于我这样的低级新手来说

The input file will contain data for one or more test cases, one test case per line. On each line there will be one or more upper case letters, separated by blank spaces.

这句话真的是一定要好好读清楚。

所以修正之后最后的代码应为：

#include<cstdio>

using namespace std;

int main(){	
	char rank;
	double score = 0.0;
	int cnt = 0;
	int flag2 = 1;
		while(scanf("%c",&rank) != EOF){
			if (rank == ' ')
				continue;
			if	(rank == '
'){
				if(flag2){
					printf("%.2f
",score/cnt);
				}else{
					printf("Unknown letter grade in input
");
				}
				flag2 = 1;
				cnt = 0;
				score = 0;
				continue;
			}
			if(rank == 'A')
				score += 4;
			else if(rank == 'B')
				score += 3;
			else if(rank == 'C')
				score += 2;
			else if(rank == 'D')
				score += 1;
			else if(rank == 'F')
				score += 0;
			else{
				flag2 = 0;
			}
			cnt ++;
		}
	return	0;
}

嗯这是第一篇，如有兴趣的朋友，也请多指正。