PAT-1137. Final Grading (25)

1137. Final Grading (25)

时间限制

100 ms

内存限制

65536 kB

代码长度限制

16000 B

判题程序

Standard

作者

CHEN, Yue

For a student taking the online course "Data Structures" on China University MOOC (http://www.icourse163.org/), to be qualified for a certificate, he/she must first obtain no less than 200 points from the online programming assignments, and then receive a final grade no less than 60 out of 100. The final grade is calculated by G = (G_mid-termx 40% + G_finalx 60%) if G_mid-term > G_final, or G_final will be taken as the final grade G. Here G_mid-term and G_final are the student's scores of the mid-term and the final exams, respectively.

The problem is that different exams have different grading sheets. Your job is to write a program to merge all the grading sheets into one.

Input Specification:

Each input file contains one test case. For each case, the first line gives three positive integers: P , the number of students having done the online programming assignments; M, the number of students on the mid-term list; and N, the number of students on the final exam list. All the numbers are no more than 10,000.

Then three blocks follow. The first block contains P online programming scores G_p's; the second one contains M mid-term scores G_mid-term's; and the last one contains N final exam scores G_final's. Each score occupies a line with the format: StudentID Score, where StudentID is a string of no more than 20 English letters and digits, and Score is a nonnegative integer (the maximum score of the online programming is 900, and that of the mid-term and final exams is 100).

Output Specification:

For each case, print the list of students who are qualified for certificates. Each student occupies a line with the format:

StudentID G_p G_mid-term G_final G

If some score does not exist, output "-1" instead. The output must be sorted in descending order of their final grades (G must be rounded up to an integer). If there is a tie, output in ascending order of their StudentID's. It is guaranteed that the StudentID's are all distinct, and there is at least one qualified student.

Sample Input:

6 6 7
01234 880
a1903 199
ydjh2 200
wehu8 300
dx86w 220
missing 400
ydhfu77 99
wehu8 55
ydjh2 98
dx86w 88
a1903 86
01234 39
ydhfu77 88
a1903 66
01234 58
wehu8 84
ydjh2 82
missing 99
dx86w 81

Sample Output:

missing 400 -1 99 99
ydjh2 200 98 82 88
dx86w 220 88 81 84
wehu8 300 55 84 84

---

提交代码

刚开始做，只得了4分，后来发现是cmp的返回值没有写全。

然后就是超时错误，这道题通过条件优化可以做到通过，还是感到新奇的，过去做ACM只要大方向没有问题，都能过的，这道题一些条件没有进行判断，在运行时间上还是有很大差别的，可能是测试用例比较特别，也可能是pat时限要求很高。

#include <bits/stdc++.h>

using namespace std;

int N, M, K;

struct Stu {
    int online = -1;
    int mid = -1;
    int fina = -1;
    int tot = -1;
    string s;
    bool operator < (const Stu &stu) const {
        return tot == stu.tot ? s < stu.s : tot > stu.tot;
    }
};

map<string, Stu> stuMap;
vector<Stu> stuVec;

int main()
{
    cin>> N>> M>> K;
    string s;
    int x;
    for(int i = 0; i < N; i++) {
        cin>>s;
        scanf("%d", &x);
        if(x >= 200) {
            stuMap[s].s = s;
            stuMap[s].online = x;
        }
    }
    for(int i = 0; i < M; i++) {
        cin>>s;
        scanf("%d", &x);
        if(stuMap.count(s)) {
            stuMap[s].mid = x;
        }
    }
    for(int i = 0; i < K; i++) {
        cin>>s;
        scanf("%d", &x);
        if(stuMap.count(s)) {
            stuMap[s].fina = x;
            if(stuMap[s].mid > stuMap[s].fina) {
                stuMap[s].tot = stuMap[s].mid*0.4+stuMap[s].fina*0.6+0.5;
            }
            else {
                stuMap[s].tot = stuMap[s].fina;
            }
            if(stuMap[s].tot >= 60)stuVec.push_back(stuMap[s]);
        }
    }
    sort(stuVec.begin(), stuVec.end());
    for(int i = 0; i < stuVec.size(); i++) {
        printf("%s %d %d %d %d
", stuVec[i].s.c_str(), stuVec[i].online, stuVec[i].mid, stuVec[i].fina, stuVec[i].tot);
    }
    return 0;
}

这是悬挂在超时边缘的代码：

#include <bits/stdc++.h>

using namespace std;

int N, M, K;

struct Stu {
    int online = -1;
    int mid = -1;
    int fina = -1;
    int tot = -1;
    //string s;
    /*bool operator < (const Stu &stu) const {
        return tot == stu.tot ? s < stu.s : tot > stu.tot;
    }*/
};

map<string, Stu> stuMap;
//vector<Stu> stuVec;
string stuNames[10004];

bool cmp(string s1, string s2) {
    return stuMap[s1].tot == stuMap[s2].tot ? s1 < s2 : stuMap[s1].tot > stuMap[s2].tot;
}

int main()
{
    cin>> N>> M>> K;
    string s;
    int x;
    for(int i = 0; i < N; i++) {
        cin>>s>>x;
        //if(x >= 200) {
            //stuMap[s].s = s;
            stuMap[s].online = x;
            stuNames[i] = s;
        //}
    }
    for(int i = 0; i < M; i++) {
        cin>>s>>x;
        //if(stuMap.count(s)) {
            stuMap[s].mid = x;
        //}
    }
    for(int i = 0; i < K; i++) {
        cin>>s>>x;
        //if(stuMap.count(s)) {
            stuMap[s].fina = x;
            if(stuMap[s].mid > stuMap[s].fina) {
                stuMap[s].tot = stuMap[s].mid*0.4+stuMap[s].fina*0.6+0.5;
            }
            else {
                stuMap[s].tot = stuMap[s].fina;
            }
            //if(stuMap[s].tot >= 60 && stuMap[s].online >= 200)stuVec.push_back(stuMap[s]);
        //}
    }
    sort(stuNames, stuNames+N, cmp);
    //sort(stuVec.begin(), stuVec.end());
    for(int i = 0; i < N; i++) {
        if(stuMap[stuNames[i]].online < 200) continue;
        if(stuMap[stuNames[i]].tot < 60) break;
        printf("%s %d %d %d %d
", stuNames[i].c_str(), stuMap[stuNames[i]].online, stuMap[stuNames[i]].mid, stuMap[stuNames[i]].fina, stuMap[stuNames[i]].tot);
    }
    return 0;
}