1012 The Best Rank (25分)
To evaluate the performance of our first year CS majored students, we consider their grades of three courses only: C - C Programming Language, M - Mathematics (Calculus or Linear Algrbra), and E - English. At the mean time, we encourage students by emphasizing on their best ranks – that is, among the four ranks with respect to the three courses and the average grade, we print the best rank for each student.
For example, The grades of C, M, E and A - Average of 4 students are given as the following:
StudentID C M E A
310101 98 85 88 90
310102 70 95 88 84
310103 82 87 94 88
310104 91 91 91 91
Then the best ranks for all the students are No.1 since the 1st one has done the best in C Programming Language, while the 2nd one in Mathematics, the 3rd one in English, and the last one in average.
Input Specification:
Each input file contains one test case. Each case starts with a line containing 2 numbers N and M (≤2000), which are the total number of students, and the number of students who would check their ranks, respectively. Then N lines follow, each contains a student ID which is a string of 6 digits, followed by the three integer grades (in the range of [0, 100]) of that student in the order of C, M and E. Then there are M lines, each containing a student ID.
Output Specification:
For each of the M students, print in one line the best rank for him/her, and the symbol of the corresponding rank, separated by a space.
The priorities of the ranking methods are ordered as A > C > M > E. Hence if there are two or more ways for a student to obtain the same best rank, output the one with the highest priority.
If a student is not on the grading list, simply output N/A.
Sample Input:
5 6
310101 98 85 88
310102 70 95 88
310103 82 87 94
310104 91 91 91
310105 85 90 90
310101
310102
310103
310104
310105
999999
Sample Output:
1 C
1 M
1 E
1 A
3 A
N/A
解题思路：
很明显这是一个排序题，每个人输出其最好的排名。从输出来看要求按照A>C>M>E的优先级输出一个人的最高排名，并根据所给的//StudentID输出结果，这就要求保存每个人的最高排名，或者保存每个人各个科目的排名，从其中选择一个最高排名。
因此需要用sort对每个科目排序，并将排名赋给//StudentID，再根据输出要求，给出//StudentID找到其最高排名。这里可以用map做StudentID->排名的映射。排名一共有四个排名，因此构建一个Rank的数据结构。最高再用map记录//StudentID与布尔类型的映射，用来记录//StudentID是否存在。
struct Rank{
int d[4];
};
比较函数
bool cmp1(Student a,Student b){
return a.c>b.c;
}
bool cmp2(Student a,Student b){
return a.m>b.m;
}
bool cmp3(Student a,Student b){
return a.e>b.e;
}
bool cmp4(Student a,Student b){
return a.a>b.a;
}
排序
sort(stu.begin(),stu.end(),cmp4);
for(int i=0;i<stu.size();i++){
if(i==0){
res[stu[i].id].d[0]=1;
}
if(stu[i].a==stu[i-1].a)
res[stu[i].id].d[0]= res[stu[i-1].id].d[0];
else
res[stu[i].id].d[0]=i+1;
}
sort(stu.begin(),stu.end(),cmp1);
for(int i=0;i<stu.size();i++){
if(i==0){
res[stu[i].id].d[1]=1;
}
if(stu[i].c==stu[i-1].c)
res[stu[i].id].d[1]= res[stu[i-1].id].d[1];
else
res[stu[i].id].d[1]=i+1;
}
sort(stu.begin(),stu.end(),cmp2);
for(int i=0;i<stu.size();i++){
if(i==0){
res[stu[i].id].d[2]=1;
}
if(stu[i].m==stu[i-1].m)
res[stu[i].id].d[2]= res[stu[i-1].id].d[2];
else
res[stu[i].id].d[2]=i+1;
}
sort(stu.begin(),stu.end(),cmp3);
for(int i=0;i<stu.size();i++){
if(i==0){
res[stu[i].id].d[3]=1;
}
if(stu[i].e==stu[i-1].e)
res[stu[i].id].d[3]= res[stu[i-1].id].d[3];
else
res[stu[i].id].d[3]=i+1;
}