【C语言】随机滚动抽奖程序，可控制概率！（附源代码及解析）

const char *names[] = {
    "John Doe", "Jane Smith", "Alice Johnson"  // 添加/修改名字
};

setProbability(0, 50);  // 将第一个参与者的中奖概率设置为 50%
setProbability(1, 30);  // 将第二个参与者的中奖概率设置为 30%

gcc lottery.c -o lottery   # 编译程序
./lottery                  # 运行程序

Enter the number of winners for this lottery: 3

Starting the lottery...

John Doe
Jane Smith
Alice Johnson

...

Winner 1: John Doe
Winner 2: Jane Smith
Winner 3: Alice Johnson

Would you like to continue the lottery? (y/n): n

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <unistd.h>  // For usleep function to create a delay

#define MAX_PEOPLE 100  // Number of participants
#define MAX_NAME_LEN 50  // Maximum length of name
#define WINNER_DELAY 1000000  // Time between each winner selection in microseconds (1 second)
#define SCROLL_DELAY 100000  // Delay for scrolling each name (100ms)

typedef struct {
    char name[MAX_NAME_LEN];  // Participant's name
    int probability;  // Probability of winning (0-100%)
} Person;

// Global array to store all participants
Person participants[MAX_PEOPLE];
int totalParticipants = 0;  // Current total number of participants
int totalProbability = 0;  // Total probability, used to balance probabilities

// Function declarations
void loadParticipants();
void setProbability(int index, int probability);  // Set probability for a specific person
void drawLottery(int drawCount);
void clearScreen();  // Function to clear the screen
void scrollNames();  // Display names one by one in a loop
void displayWinners(int winners[], int winnerCount);  // Function to display the winners

// Main function
int main() {
    srand(time(NULL));  // Set the random seed

    // Load participant information
    loadParticipants();

    // Set special participants' probabilities (can be customized)
    //setProbability(0, 100);  // Set 100% probability for participant 0 (e.g., John Doe)
    //setProbability(1, 100);  // Set 100% probability for participant 1 (e.g., Jane Smith)
    //setProbability(2, 50);   // Set 50% probability for participant 2 (e.g., Alice Johnson)

    // Main loop for lottery drawing
    while (1) {
        int drawCount;
        printf("\nEnter the number of winners for this lottery: ");
        scanf("%d", &drawCount);

        // Conduct the lottery
        drawLottery(drawCount);

        // Ask if the user wants to conduct another lottery
        char choice;
        printf("\nWould you like to continue the lottery? (y/n): ");
        getchar();  // Clear the buffer
        choice = getchar();
        if (choice != 'y' && choice != 'Y') {
            break;
        }
    }

    return 0;
}

// Load participant information (example names)
void loadParticipants() {
    // Example names for participants (can be modified to any number of participants)
    const char *names[] = {
        "John Doe", "Jane Smith", "Alice Johnson", "Bob Brown", "Charlie Davis", 
        "David Miller", "Eve Wilson", "Frank Moore", "Grace Taylor", "Hank Anderson", 
        "Ivy Thomas", "Jack Jackson", "Kathy White", "Leo Harris", "Mona Clark", 
        "Nina Lewis", "Oscar Walker", "Paul Young", "Quincy King", "Rachel Scott", 
        "Steve Adams", "Tina Baker", "Ursula Nelson", "Victor Carter", "Wendy Mitchell", 
        "Xander Roberts", "Yara Perez", "Zachary Cooper", "Abigail Green", "Benjamin Hill", 
        "Chloe Hall", "Daniel Lopez", "Ella Scott", "Freddie Allen", "Georgia King", 
        "Holly Wright", "Isaac Lee", "Jasmine Walker", "Kurt Martinez", "Lily Evans", 
        "Mark White", "Nora Baker", "Oliver Harris", "Penelope Carter", "Quinn Young", 
        "Rachel Smith", "Sophie Brown", "Tom Nelson", "Ursula Davis", "Vince Clark"
    };

    // Calculate the number of participants from the names array length
    int numParticipants = sizeof(names) / sizeof(names[0]);

    // Copy these names into the participants array and initialize their probabilities
    for (int i = 0; i < numParticipants; i++) {
        snprintf(participants[i].name, MAX_NAME_LEN, "%s", names[i]);
        participants[i].probability = 2;  // Default probability is 2% for everyone
        totalProbability += participants[i].probability;  // Update the total probability
    }

    totalParticipants = numParticipants;  // Set the total number of participants
}

// Set the probability for a specific participant (0-100%)
void setProbability(int index, int probability) {
    if (index >= 0 && index < totalParticipants) {
        totalProbability -= participants[index].probability;  // Subtract the old probability
        participants[index].probability = probability;  // Set the new probability
        totalProbability += probability;  // Add the new probability to the total
    }
}

// Function to clear the screen (use "cls" for Windows, "clear" for Linux/Mac)
void clearScreen() {
#ifdef _WIN32
    system("cls");
#else
    system("clear");
#endif
}

// Function to display all names scrolling one by one in order
void scrollNames() {
    // Scroll through all participants' names in order
    for (int i = 0; i < totalParticipants; i++) {
        clearScreen();  // Clear the screen before displaying the next name
        printf("%s\n", participants[i].name);  // Display one name at a time
        usleep(SCROLL_DELAY);  // Delay in microseconds (controlled by SCROLL_DELAY macro)
    }
}

// Function to display the winners list
void displayWinners(int winners[], int winnerCount) {
    printf("\nThe winners of this lottery are:\n");
    for (int i = 0; i < winnerCount; i++) {
        printf("Winner %d: %s\n", i + 1, participants[winners[i]].name);
    }
}

// Lottery drawing function
void drawLottery(int drawCount) {
    printf("\nStarting the lottery...\n");

    int winners[drawCount];  // Array to store indices of winners
    int winnerCount = 0;

    // Initialize winners array to -1 (no winners initially)
    for (int i = 0; i < drawCount; i++) {
        winners[i] = -1;
    }

    // First, scroll through all participant names (No winners displayed during this)
    scrollNames();

    // Start the drawing process after the scrolling is done
    printf("\nDrawing the winners...\n");
    while (winnerCount < drawCount) {
        // Randomly select a winner considering probabilities
        int winnerIndex = rand() % totalProbability;  // Randomly select a number between 0 and totalProbability

        // Find the winner by checking the probability ranges
        int cumulativeProbability = 0;
        for (int i = 0; i < totalParticipants; i++) {
            cumulativeProbability += participants[i].probability;
            if (winnerIndex < cumulativeProbability) {
                // Check if the person has already won
                int alreadyWon = 0;
                for (int j = 0; j < winnerCount; j++) {
                    if (winners[j] == i) {
                        alreadyWon = 1;
                        break;
                    }
                }

                if (!alreadyWon) {
                    winners[winnerCount] = i;
                    winnerCount++;
                    clearScreen();  // Clear screen before displaying the next winner
                    displayWinners(winners, winnerCount);  // Display the current winners
                    usleep(WINNER_DELAY);  // Delay between each winner selection
                }
                break;
            }
        }
    }

    // After all winners are selected, display the final list
    clearScreen();
    printf("Lottery Ended\n");
    displayWinners(winners, winnerCount);  // Display the final list of winners
}

Person

drawLottery