C Programming: Number Guessing Game Tutorial – Complete Guide with Source Code

The number guessing game is a perfect beginner project in C programming that teaches essential concepts like random number generation, loops, conditional statements, and user input handling. This comprehensive tutorial includes multiple versions from basic to advanced implementations.

What You’ll Learn

• Random number generation using srand() and rand()
• Game loops and user interaction patterns
• Conditional logic and decision making
• Input validation and error handling
• Building interactive console applications

Basic Number Guessing Game

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

int main() {
    int secretNumber, userGuess, attempts = 0;
    
    // Initialize random seed
    srand(time(NULL));
    
    // Generate random number between 1 and 100
    secretNumber = rand() % 100 + 1;
    
    printf("==========================================\n");
    printf("        NUMBER GUESSING GAME             \n");
    printf("==========================================\n");
    printf("I'm thinking of a number between 1 and 100.\n");
    printf("Can you guess what it is?\n\n");
    
    do {
        printf("Enter your guess: ");
        scanf("%d", &userGuess);
        attempts++;
        
        if (userGuess < secretNumber) {
            printf("Too low! Try again.\n\n");
        } else if (userGuess > secretNumber) {
            printf("Too high! Try again.\n\n");
        } else {
            printf("\nCongratulations! You guessed it!\n");
            printf("The number was %d\n", secretNumber);
            printf("You took %d attempts.\n", attempts);
            
            // Performance evaluation
            if (attempts <= 3) {
                printf("Excellent! You're a guessing master!\n");
            } else if (attempts <= 6) {
                printf("Good job! Nice guessing skills!\n");
            } else if (attempts <= 10) {
                printf("Not bad! You got there in the end!\n");
            } else {
                printf("You made it! Practice makes perfect!\n");
            }
        }
        
    } while (userGuess != secretNumber);
    
    return 0;
}

Enhanced Version with Difficulty Levels

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

int playGame(int maxNumber, int maxAttempts) {
    int secretNumber, userGuess, attempts = 0;
    
    secretNumber = rand() % maxNumber + 1;
    
    printf("\nI'm thinking of a number between 1 and %d.\n", maxNumber);
    if (maxAttempts > 0) {
        printf("You have %d attempts to guess it!\n\n", maxAttempts);
    } else {
        printf("You have unlimited attempts!\n\n");
    }
    
    do {
        printf("Attempt %d: Enter your guess: ", attempts + 1);
        scanf("%d", &userGuess);
        attempts++;
        
        if (userGuess < secretNumber) {
            printf("Too low!");
            if (maxAttempts > 0) {
                printf(" (%d attempts remaining)", maxAttempts - attempts);
            }
            printf("\n");
        } else if (userGuess > secretNumber) {
            printf("Too high!");
            if (maxAttempts > 0) {
                printf(" (%d attempts remaining)", maxAttempts - attempts);
            }
            printf("\n");
        } else {
            printf("\nCONGRATULATIONS!\n");
            printf("You guessed the number %d correctly!\n", secretNumber);
            printf("It took you %d attempts.\n", attempts);
            return 1; // Success
        }
        
        // Check if max attempts reached
        if (maxAttempts > 0 && attempts >= maxAttempts) {
            printf("\nGAME OVER!\n");
            printf("You've used all %d attempts.\n", maxAttempts);
            printf("The number was %d.\n", secretNumber);
            return 0; // Failure
        }
        
    } while (userGuess != secretNumber);
    
    return 1;
}

int main() {
    int choice;
    char playAgain;
    
    srand(time(NULL));
    
    printf("==========================================\n");
    printf("    ADVANCED NUMBER GUESSING GAME        \n");
    printf("==========================================\n");
    
    do {
        printf("\nSelect difficulty level:\n");
        printf("1. Easy (1-50, unlimited attempts)\n");
        printf("2. Medium (1-100, 10 attempts)\n");
        printf("3. Hard (1-500, 8 attempts)\n");
        printf("4. Expert (1-1000, 6 attempts)\n");
        printf("Enter your choice: ");
        scanf("%d", &choice);
        
        switch (choice) {
            case 1:
                printf("\n=== EASY MODE ===");
                playGame(50, 0);
                break;
            case 2:
                printf("\n=== MEDIUM MODE ===");
                playGame(100, 10);
                break;
            case 3:
                printf("\n=== HARD MODE ===");
                playGame(500, 8);
                break;
            case 4:
                printf("\n=== EXPERT MODE ===");
                playGame(1000, 6);
                break;
            default:
                printf("Invalid choice! Please try again.\n");
                continue;
        }
        
        printf("\nWould you like to play again? (y/n): ");
        scanf(" %c", &playAgain);
        
    } while (playAgain == 'y' || playAgain == 'Y');
    
    printf("Thanks for playing! Goodbye!\n");
    return 0;
}

Version with Hints and Statistics

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>

typedef struct {
    int gamesPlayed;
    int gamesWon;
    int totalAttempts;
    int bestScore;
} GameStats;

void displayStats(GameStats stats) {
    printf("\n=== YOUR STATISTICS ===\n");
    printf("Games Played: %d\n", stats.gamesPlayed);
    printf("Games Won: %d\n", stats.gamesWon);
    if (stats.gamesPlayed > 0) {
        printf("Win Rate: %.1f%%\n", (float)stats.gamesWon / stats.gamesPlayed * 100);
    }
    if (stats.gamesWon > 0) {
        printf("Average Attempts: %.1f\n", (float)stats.totalAttempts / stats.gamesWon);
        printf("Best Score: %d attempts\n", stats.bestScore);
    }
    printf("======================\n");
}

int playGameWithHints() {
    int secretNumber, userGuess, attempts = 0;
    int lower = 1, upper = 100;
    char wantHint;
    
    secretNumber = rand() % 100 + 1;
    
    printf("\n=== GAME WITH HINTS ===\n");
    printf("I'm thinking of a number between 1 and 100.\n");
    printf("You can ask for hints after 3 attempts!\n\n");
    
    do {
        printf("Range: %d to %d\n", lower, upper);
        printf("Attempt %d: Enter your guess: ", attempts + 1);
        scanf("%d", &userGuess);
        attempts++;
        
        if (userGuess < secretNumber) {
            printf("Too low!\n");
            if (userGuess >= lower) {
                lower = userGuess + 1;
            }
        } else if (userGuess > secretNumber) {
            printf("Too high!\n");
            if (userGuess <= upper) {
                upper = userGuess - 1;
            }
        } else {
            printf("\nPERFECT! You found it!\n");
            printf("The number was %d\n", secretNumber);
            printf("You needed %d attempts.\n", attempts);
            return attempts;
        }
        
        // Offer hint after 3 attempts
        if (attempts >= 3 && attempts % 2 == 1) {
            printf("Would you like a hint? (y/n): ");
            scanf(" %c", &wantHint);
            
            if (wantHint == 'y' || wantHint == 'Y') {
                if (secretNumber % 2 == 0) {
                    printf("Hint: The number is EVEN.\n");
                } else {
                    printf("Hint: The number is ODD.\n");
                }
                
                if (attempts >= 5) {
                    int digitSum = 0;
                    int temp = secretNumber;
                    while (temp > 0) {
                        digitSum += temp % 10;
                        temp /= 10;
                    }
                    printf("Bonus hint: Sum of digits is %d.\n", digitSum);
                }
            }
        }
        
        printf("\n");
        
    } while (userGuess != secretNumber);
    
    return attempts;
}

int main() {
    GameStats stats = {0, 0, 0, 0};
    int choice, attempts;
    char playerName[50];
    
    srand(time(NULL));
    
    printf("==========================================\n");
    printf("    NUMBER GUESSING GAME WITH HINTS      \n");
    printf("==========================================\n");
    
    printf("Enter your name: ");
    fgets(playerName, sizeof(playerName), stdin);
    playerName[strcspn(playerName, "\n")] = 0; // Remove newline
    
    printf("Hello %s! Welcome to the guessing game!\n", playerName);
    
    do {
        printf("\n=== MAIN MENU ===\n");
        printf("1. Play Game\n");
        printf("2. View Statistics\n");
        printf("3. Exit\n");
        printf("Enter your choice: ");
        scanf("%d", &choice);
        
        switch (choice) {
            case 1:
                stats.gamesPlayed++;
                attempts = playGameWithHints();
                
                stats.gamesWon++;
                stats.totalAttempts += attempts;
                
                if (stats.bestScore == 0 || attempts < stats.bestScore) {
                    stats.bestScore = attempts;
                    printf("NEW BEST SCORE!\n");
                }
                
                // Performance feedback
                if (attempts <= 5) {
                    printf("Outstanding performance!\n");
                } else if (attempts <= 8) {
                    printf("Great job!\n");
                } else if (attempts <= 12) {
                    printf("Good effort!\n");
                } else {
                    printf("Keep practicing!\n");
                }
                break;
                
            case 2:
                displayStats(stats);
                break;
                
            case 3:
                printf("\nThanks for playing, %s!\n", playerName);
                displayStats(stats);
                printf("Goodbye!\n");
                break;
                
            default:
                printf("Invalid choice! Please try again.\n");
        }
        
    } while (choice != 3);
    
    return 0;
}

Key Programming Concepts

Random Number Generation: The programs use srand(time(NULL)) for seeding and rand() for generating random numbers within specific ranges.

Control Structures: Various loop types including do-while and while loops demonstrate different approaches to game flow control.

Function Design: The advanced versions show how to organize code into reusable functions for better maintainability.

Data Structures: The statistics version uses structures to organize related game data efficiently.

Compilation and Usage

# Compile any version
gcc guessing_game.c -o guessing_game

# Run the program
./guessing_game

Practice Exercises

1. Add a two-player mode where players take turns
2. Implement a time limit for each guess
3. Create custom difficulty with user-defined ranges
4. Add file saving for persistent high scores
5. Build a graphical progress indicator

Conclusion

The number guessing game is an excellent introduction to C programming fundamentals. It combines essential concepts like random number generation, loops, conditionals, and user interaction in an engaging format. These examples demonstrate progressive complexity from basic implementations to feature-rich applications with statistics tracking and hint systems.