bài 3 4 bổ sung

[phantrantruonghuy]

include

include

int main() { int choice; printf("Moi ban chon bai tap (1-10): "); scanf("%d", &choice);

switch (choice) {
    case 1: {
        int num1, num2;
        printf("Nhap vao hai so nguyen: ");
        scanf("%d %d", &num1, &num2);
        printf("Tong: %d\n", num1 + num2);
        printf("Hieu: %d\n", num1 - num2);
        printf("Tich: %d\n", num1 * num2);
        if (num2 != 0) {
            printf("Thuong: %.2f\n", (float)num1 / num2);
        } else {
            printf("Khong the chia cho 0.\n");
        }
        break;
    }
    case 2: {
        int number;
        printf("Nhap vao mot so co 3 chu so: ");
        scanf("%d", &number);
        int sum = 0;
        int product = 1;

        while (number > 0) {
            int digit = number % 10;
            sum += digit;
            product *= digit;
            number /= 10;
        }

        printf("Tong: %d\n", sum);
        printf("Tich: %d\n", product);
        break;
    }
    case 3: {
        int a, b;
        printf("Nhap vao hai so nguyen: ");
        scanf("%d %d", &a, &b);
        printf("So lon nhat: %d\n", (a > b) ? a : b);
        printf("So nho nhat: %d\n", (a < b) ? a : b);
        break;
    }
    case 4: {
        float toan, ly, hoa;
        printf("Nhap diem Toan, Ly, Hoa cua hoc sinh: ");
        scanf("%f %f %f", &toan, &ly, &hoa);
        float diemTB = (toan + ly + hoa) / 3;
        printf("Diem trung binh: %.2f\n", diemTB);

        if (diemTB >= 9.0) {
            printf("Xuat sac\n");
        } else if (diemTB >= 8.0) {
            printf("Gioi\n");
        } else if (diemTB >= 6.5) {
            printf("Kha\n");
        } else if (diemTB >= 5.0) {
            printf("Trung binh\n");
        } else if (diemTB >= 3.5) {
            printf("Yeu\n");
        } else {
            printf("Kem\n");
        }
        break;
    }
    case 5: {
        float a, b;
        printf("Nhap a va b: ");
        scanf("%f %f", &a, &b);
        if (a == 0) {
            if (b == 0) {
                printf("Phuong trinh co vo so nghiem.\n");
            } else {
                printf("Phuong trinh vo nghiem.\n");
            }
        } else {
            float x = -b / a;
            printf("Nghiem cua phuong trinh: x = %.2f\n", x);
        }
        break;
    }
    case 6: {
        int day;
        printf("Nhap vao so nguyen tu 1 den 7: ");
        scanf("%d", &day);
        switch (day) {
            case 1:
                printf("Sunday\n");
                break;
            case 2:
                printf("Monday\n");
                break;
            case 3:
                printf("Tuesday\n");
                break;
            case 4:
                printf("Wednesday\n");
                break;
            case 5:
                printf("Thursday\n");
                break;
            case 6:
                printf("Friday\n");
                break;
            case 7:
                printf("Saturday\n");
                break;
            default:
                printf("So khong hop le.\n");
                break;
        }
        break;
    }
    case 7: {
        float side1, side2, side3;
        printf("Nhap vao 3 so thuc a, b, c: ");
        scanf("%f %f %f", &side1, &side2, &side3);
        if (side1 + side2 > side3 && side1 + side3 > side2 && side2 + side3 > side1) {
            printf("Day la mot tam giac. ");
            if (side1 == side2 && side2 == side3) {
                printf("Tam giac deu.\n");
            } else if (side1 == side2 || side1 == side3 || side2 == side3) {
                if (side1 * side1 + side2 * side2 == side3 * side3 || side1 * side1 + side3 * side3 == side2 * side2 || side2 * side2 + side3 * side3 == side1 * side1) {
                    printf("Tam giac vuong can.\n");
                } else {
                    printf("Tam giac can.\n");
                }
            } else if (side1 * side1 + side2 * side2 == side3 * side3 || side1 * side1 + side3 * side3 == side2 * side2 || side2 * side2 + side3 * side3 == side1 * side1) {
                printf("Tam giac vuong.\n");
            } else {
                printf("Tam giac thuong.\n");
            }

            float p = (side1 + side2 + side3) / 2;
            float area = sqrt(p * (p - side1) * (p - side2) * (p - side3));
            printf("Dien tich: %.2f\n", area);
            printf("Chieu dai cac duong cao: ha = %.2f, hb = %.2f, hc = %.2f\n", (2 * area / side1), (2 * area / side2), (2 * area / side3));
        } else {
            printf("Day khong phai la tam giac.\n");
        }
        break;
    }
    case 8: {
        float a, b, c;
        printf("Nhap a, b, va c: ");
        scanf("%f %f %f", &a, &b, &c);
        if (a == 0) {
            if (b == 0) {
                if (c == 0) {
                    printf("Phuong trinh co vo so nghiem.\n");
                } else {
                    printf("Phuong trinh vo nghiem.\n");
                }
            } else {
                float x = -c / b;
                printf("Nghiem cua phuong trinh: x = %.2f\n", x);
            }
        } else {
            float discriminant = b * b - 4 * a * c;
            if (discriminant > 0) {
                float x1 = (-b + sqrt(discriminant)) / (2 * a);
                float x2 = (-b - sqrt(discriminant)) / (2 * a);
                printf("Phuong trinh co 2 nghiem: x1 = %.2f, x2 = %.2f\n", x1, x2);
            } else if (discriminant == 0) {
                float x = -b / (2 * a);
                printf("Phuong trinh co nghiem kep: x = %.2f\n", x);
            } else {
                printf("Phuong trinh vo nghiem.\n");
            }
        }
        break;
    }
    case 9: {
        char c;
        printf("Nhap mot chu cai: ");
        scanf(" %c", &c);
        if (c >= 'a' && c <= 'z') {
            c = c - 32;
        } else if (c >= 'A' && c <= 'Z') {
            c = c + 32;
        }
        printf("Ket qua: %c\n", c);
        break;
    }
    case 10: {
        int kwh;
        printf("Nhap so Kwh tieu thu: ");
        scanf("%d", &kwh);
        float totalCost = 0;
        if (kwh <= 100) {
            totalCost = kwh * 455.0;
        } else if (kwh <= 150) {
            totalCost = 100 * 455.0 + (kwh - 100) * 591.0;
        } else if (kwh <= 200) {
            totalCost = 100 * 455.0 + 50 * 591.0 + (kwh - 150) * 818.0;
        } else {
            totalCost = 100 * 455.0 + 50 * 591.0 + 50 * 818.0 + (kwh - 200) * 1000.0;
        }
        printf("Tien dien phai tra: %.2f VND\n", totalCost);
        break;
    }
    default:
        printf("Lua chon khong hop le.\n");
}

return 0;

}

[puudynk05]

so pro