University student IDs consist of nine digits.
The first digit represents the student's status (for example, "B" for undergraduate students). The second and third digits represent the last two digits of the admission year. The fourth, fifth, sixth, and seventh digits represent the codes for college, department, and group. The eighth and ninth digits represent the student's serial number.
This question assumes that the university always has the following colleges, departments, and groups (please refer to the sample input for all college, department, and group codes):
－1000 College of Liberal Arts
－2000 College of Science
－3000 College of Social Sciences
－And so on...
This question assumes that each group can admit 100 students (the eighth and ninth digits range from "00" to "99").
Now, from a pile of university student IDs, ten IDs are randomly selected. Write a program to verify if these ten IDs are valid and calculate the error rate.
For example, for the following ten student IDs:
B00100000 R00100000 // Does not match the code for undergraduate students BA0100000 // Does not match the code for admission year B00101300 // Does not match the code for department and group B001000A0 // Does not match the code for serial number B09902005 B06A01233 B12701256 B80310020 B98901030
The result is Y, N, N, N, N, Y, Y, Y, Y, Y. The error rate is 0.4.
Sample Inputs/Outputs
| Sample Input(s) | Sample Output(s) |
|---|---|
| The first line of input consists of a positive integer N (1≤N≤76), representing that there are N departments or groups. Next, there are N lines of text, Each line consists of four characters representing the codes for the colleges, departments, and groups. Finally, there are 10 lines of text. Each line consists of nine characters representing the student IDs to be validated. | If the validation is successful, output "Y"; if it fails, output "N." Finally, output the failure rate of the validation. |
| 76 0000 1000 1010 1011 1020 1030 1040 1050 1060 1070 1090 2000 2010 2020 2030 2040 2070 2080 2090 3000 3021 3022 3023 3030 3050 3100 4000 4010 4020 4030 4031 4040 4060 4080 4081 4090 4120 5000 5010 5020 5040 5050 5070 5080 6000 6010 6020 6030 6050 6060 6070 6080 6090 6100 6110 6120 6130 7000 7011 7012 7020 7030 7040 7050 8000 8010 9000 9010 9020 A000 A011 A012 A013 B000 B010 B020 B00100000 R00100000 BA0100000 B00101300 B001000A0 B09902005 B06A01233 B12701256 B80310020 B98901030 | Y N N N N Y Y Y Y Y 0.4 |
Thought Process
You can use a map to check if the middle four characters have appeared before. When outputting the failure rate, if there are no validation failures, output "0" instead of "0.0". If all fail, output "1" instead of "0.10" or "1.0".
Sample Code－ZeroJudge E925: Verifying Student ID
#include <iostream>
#include <map>
#include <cctype>
using namespace std;
int main() {
int N;
cin >> N;
map<string, int>MAP;
for (int i = 0; i<N; i++)
{
string str;
cin >> str;
MAP[str]++;
}
int wrong = 0;
for (int i = 0; i<10; i++)
{
string str;
cin >> str;
if (str[0] != 'B')
{
wrong++;
cout << "N\n";
continue;
}
if (!isdigit(str[1]) || !isdigit(str[2]))
{
wrong++;
cout << "N\n";
continue;
}
string tmp = "";
for (int j = 3; j<=6; j++)
{
tmp += str[j];
}
if (MAP[tmp] == 0)
{
wrong++;
cout << "N\n";
continue;
}
if (!isdigit(str[7]) || !isdigit(str[8]))
{
wrong++;
cout << "N\n";
continue;
}
cout << "Y\n";
}
if (wrong == 0) cout << 0 << "\n";
else if (wrong == 10) cout << 1 << "\n";
else cout << "0." << wrong << "\n";
}
//ZeroJudge E925
//Dr. SeanXD