🎓 C++ 综合应用 - L20 高级概念

#include <iostream> #include <string> using namespace std; // 全局变量 string names[50]; int chinese[50], math[50], english[50]; int total[50]; double average[50]; int studentCount = 0; // 函数：录入学生成绩 void addStudent() { if (studentCount >= 50) { cout << "错误：学生数量已达上限！" << endl; return; } cout << "\n=== 录入学生成绩 ===" << endl; cout << "请输入姓名："; cin >> names[studentCount]; cout << "请输入语文成绩："; cin >> chinese[studentCount]; cout << "请输入数学成绩："; cin >> math[studentCount]; cout << "请输入英语成绩："; cin >> english[studentCount]; // 计算总分和平均分 total[studentCount] = chinese[studentCount] + math[studentCount] + english[studentCount]; average[studentCount] = (double)total[studentCount] / 3; studentCount++; cout << "录入成功！" << endl; } int main() { addStudent(); return 0; }

// 函数：显示所有学生信息 void displayAllStudents() { if (studentCount == 0) { cout << "\n暂无学生数据！" << endl; return; } cout << "\n=== 所有学生信息 ===" << endl; cout << "------------------------------------------------------------" << endl; cout << "序号\t姓名\t语文\t数学\t英语\t总分\t平均分" << endl; cout << "------------------------------------------------------------" << endl; for (int i = 0; i < studentCount; i++) { cout << (i+1) << "\t"; cout << names[i] << "\t"; cout << chinese[i] << "\t"; cout << math[i] << "\t"; cout << english[i] << "\t"; cout << total[i] << "\t"; cout << average[i] << endl; } cout << "------------------------------------------------------------" << endl; cout << "共 " << studentCount << " 名学生" << endl; }

// 函数：查询学生 void searchStudent() { if (studentCount == 0) { cout << "\n暂无学生数据！" << endl; return; } string searchName; cout << "\n请输入要查询的姓名："; cin >> searchName; bool found = false; for (int i = 0; i < studentCount; i++) { if (names[i] == searchName) { cout << "\n找到学生：" << endl; cout << "姓名：" << names[i] << endl; cout << "语文：" << chinese[i] << endl; cout << "数学：" << math[i] << endl; cout << "英语：" << english[i] << endl; cout << "总分：" << total[i] << endl; cout << "平均分：" << average[i] << endl; found = true; break; } } if (!found) { cout << "未找到姓名为 \"" << searchName << "\" 的学生" << endl; } }

// 函数：统计分析 void showStatistics() { if (studentCount == 0) { cout << "\n暂无学生数据！" << endl; return; } // 计算各科统计 int chiSum = 0, chiMax = chinese[0], chiMin = chinese[0]; int mathSum = 0, mathMax = math[0], mathMin = math[0]; int engSum = 0, engMax = english[0], engMin = english[0]; for (int i = 0; i < studentCount; i++) { chiSum += chinese[i]; mathSum += math[i]; engSum += english[i]; if (chinese[i] > chiMax) chiMax = chinese[i]; if (chinese[i] < chiMin) chiMin = chinese[i]; if (math[i] > mathMax) mathMax = math[i]; if (math[i] < mathMin) mathMin = math[i]; if (english[i] > engMax) engMax = english[i]; if (english[i] < engMin) engMin = english[i]; } cout << "\n=== 统计分析 ===" << endl; cout << "科目\t平均分\t最高分\t最低分" << endl; cout << "----------------------------------------" << endl; cout << "语文\t" << (double)chiSum/studentCount << "\t" << chiMax << "\t" << chiMin << endl; cout << "数学\t" << (double)mathSum/studentCount << "\t" << mathMax << "\t" << mathMin << endl; cout << "英语\t" << (double)engSum/studentCount << "\t" << engMax << "\t" << engMin << endl; }

// 函数：按总分排名 void showRanking() { if (studentCount == 0) { cout << "\n暂无学生数据！" << endl; return; } // 创建索引数组，避免打乱原数据 int index[50]; for (int i = 0; i < studentCount; i++) { index[i] = i; } // 冒泡排序（按总分降序） for (int i = 0; i < studentCount - 1; i++) { for (int j = 0; j < studentCount - 1 - i; j++) { if (total[index[j]] < total[index[j+1]]) { int temp = index[j]; index[j] = index[j+1]; index[j+1] = temp; } } } cout << "\n=== 成绩排名 ===" << endl; cout << "排名\t姓名\t总分\t平均分" << endl; cout << "----------------------------------------" << endl; for (int i = 0; i < studentCount; i++) { int idx = index[i]; cout << (i+1) << "\t"; cout << names[idx] << "\t"; cout << total[idx] << "\t"; cout << average[idx] << endl; } }

// 函数：删除学生 void deleteStudent() { if (studentCount == 0) { cout << "\n暂无学生数据！" << endl; return; } string delName; cout << "\n请输入要删除的姓名："; cin >> delName; int delIndex = -1; for (int i = 0; i < studentCount; i++) { if (names[i] == delName) { delIndex = i; break; } } if (delIndex == -1) { cout << "未找到该学生！" << endl; return; } // 删除：后面的元素前移 for (int i = delIndex; i < studentCount - 1; i++) { names[i] = names[i+1]; chinese[i] = chinese[i+1]; math[i] = math[i+1]; english[i] = english[i+1]; total[i] = total[i+1]; average[i] = average[i+1]; } studentCount--; cout << "删除成功！" << endl; }

// 函数：显示主菜单 void showMenu() { cout << "\n========================================" << endl; cout << " 学生成绩管理系统 v1.0" << endl; cout << "========================================" << endl; cout << " 1. 录入学生成绩" << endl; cout << " 2. 显示所有学生" << endl; cout << " 3. 查询学生" << endl; cout << " 4. 统计分析" << endl; cout << " 5. 成绩排名" << endl; cout << " 6. 删除学生" << endl; cout << " 0. 退出系统" << endl; cout << "========================================" << endl; cout << "请选择功能："; } // 主函数 int main() { int choice; do { showMenu(); cin >> choice; switch (choice) { case 1: addStudent(); break; case 2: displayAllStudents(); break; case 3: searchStudent(); break; case 4: showStatistics(); break; case 5: showRanking(); break; case 6: deleteStudent(); break; case 0: cout << "\n感谢使用，再见！" << endl; break; default: cout << "\n无效选择，请重新输入！" << endl; } } while (choice != 0); return 0; }