python/RuMenJingDian/UVa/UVa12412.cpp

#include <bits/stdc++.h>

using namespace std;

const int MAXL = 100;
const int MAXN = 1000;
const double EPS = 10e-5;
int removed[MAXN];            //置1表示已移除
int n = 0;
char sid[MAXN][MAXL];
char name[MAXN][MAXL];
char cid[MAXN];
int score[MAXN][10];          //四科分数及总分

const char *course_name[] = {"Chinese", "Mathematics", "English", "Programming"};

void print_menu() {
    printf("Welcome to Student Performance Management System (SPMS).\n");
    printf("\n");
    printf("1 - Add\n");
    printf("2 - Remove\n");
    printf("3 - Query\n");
    printf("4 - Show ranking\n");
    printf("5 - Show Statistics\n");
    printf("0 - Exit\n");
    printf("\n");
}

int valid(int k)                         //判断输入的学号是否已存在
{
    for (int i = 0; i < k; i++)
        if (!removed[i]) {
            if (strcmp(sid[i], sid[k]) == 0) return 0;
        }
    return 1;
}

void add() {
    for (;;) {
        printf("Please enter the SID, CID, name and four scores. Enter 0 to finish.\n");
        scanf("%s", sid[n]);
        if (strcmp(sid[n], "0") == 0) break;
        scanf("%d%s%d%d%d%d", &cid[n], name[n], &score[n][0], &score[n][1], &score[n][2], &score[n][3]);
        if (valid(n)) {
            score[n][4] = score[n][0] + score[n][1] + score[n][2] + score[n][3];
            n++;
        }
        else printf("Duplicated SID.\n");                                        //非法输入
    }
}

int rankk(int k)         //通过统计分数大于k的人数实现排名
{
    int r = 0;
    for (int i = 0; i < n; i++)
        if (!removed[i] && score[i][4] > score[k][4]) r++;
    return r + 1;
}

void DQ(int isq)   //查询和删除操作输入要求相同，二者的处理相似，放在一个函数中处理，1为查询
{
    char s[MAXL];
    for (;;) {
        printf("Please enter SID or name. Enter 0 to finish.\n");
        scanf("%s", s);
        if (strcmp(s, "0") == 0) break;
        int r = 0;
        for (int i = 0; i < n; i++)
            if (!removed[i]) {
                if (strcmp(sid[i], s) == 0 || strcmp(name[i], s) == 0)   //枚举找到匹配的
                {
                    if (isq)
                        printf("%d %s %d %s %d %d %d %d %d %.2f\n", rankk(i), sid[i], cid[i], name[i], score[i][0],
                               score[i][1], score[i][2], score[i][3], score[i][4], score[i][4] / 4.0 + EPS);
                    else {
                        removed[i] = 1;
                        r++;
                    }  //删除并统计删除的人数
                }
            }
        if (!isq) printf("%d student(s) removed.\n", r);
    }
}

double get_course_stat(int c, int s, int *passed, int *failed)      //函数统计通过和不及格人数，并返回平均值
{
    int tot = 0;
    *passed = *failed = 0;
    for (int i = 0; i < n; i++)
        if (!removed[i] && (c == 0 || cid[i] == c)) {
            tot += score[i][s];
            if (score[i][s] >= 60) (*passed)++; else (*failed)++;
        }
    return (double) tot / (double) (*passed + *failed);
}

void get_overall_stat(int c, int *cnt)                    //返回该班通过科目为k的人数
{
    cnt[0] = cnt[1] = cnt[2] = cnt[3] = cnt[4] = 0;
    for (int i = 0; i < n; i++)
        if (!removed[i] && (c == 0 || cid[i] == c)) {
            int k = 0;
            for (int j = 0; j < 4; j++) if (score[i][j] >= 60) k++;
            cnt[k]++;
        }
}

void stat() {
    int c;
    printf("Please enter class ID, 0 for the whole statistics.\n");
    scanf("%d", &c);
    for (int i = 0; i < 4; i++)                                 //计算并打印该班各科情况
    {
        int passed, failed;
        double avg = get_course_stat(c, i, &passed, &failed);
        printf("%s\n", course_name[i]);
        printf("Average Score: %.2f\n", avg + EPS);
        printf("Number of passed students: %d\n", passed);
        printf("Number of failed students: %d\n", failed);
        printf("\n");
    }
    int cnt[5];
    get_overall_stat(c, cnt);

    printf("Overall:\n");                                                //打印通过科目数对应的人数
    printf("Number of students who passed all subjects: %d\n", cnt[4]);
    printf("Number of students who passed 3 or more subjects: %d\n", cnt[4] + cnt[3]);
    printf("Number of students who passed 2 or more subjects: %d\n", cnt[4] + cnt[3] + cnt[2]);
    printf("Number of students who passed 1 or more subjects: %d\n", cnt[4] + cnt[3] + cnt[2] + cnt[1]);
    printf("Number of students who failed all subjects: %d\n", cnt[0]);
    printf("\n");
}

int main() {
    for (;;) {
        int op;
        print_menu();
        cin >> op;
        if (op == 0) break;
        if (op == 1) add();
        if (op == 2) DQ(0);
        if (op == 3) DQ(1);
        if (op == 4) printf("Showing the ranklist hurts students' self-esteem. Don't do that.\n");   //  (|||- -)
        if (op == 5) stat();
    }
    return 0;
}