C语言数字猜谜游戏问题求助：无论输入何值均判定错误

Hey there! Let's troubleshoot your number guessing game issue. I see your code snippet cuts off at char instri..., but based on your description that any input gets incorrectly marked as wrong, here are the most common causes and fixes:

1. Mismatched Variable Types #

This is the #1 culprit here! rand() returns an integer (int), but if you're storing your user's guess in a char variable (like your cut-off char instri... suggests), the values won't compare correctly.

You need to use int for both the target number and the user's guess. Here's a corrected core structure:

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

int main(void) {
    srand(time(NULL));
    // Generate a random number between 1 and 100 (adjust range as needed)
    int target_number = rand() % 100 + 1;
    int user_guess;

    printf("Guess a number between 1 and 100: ");
    // Use %d to read an integer, and pass the address of user_guess with &
    scanf("%d", &user_guess);

    if (user_guess > target_number) {
        printf("too high\n");
    } else if (user_guess < target_number) {
        printf("too low\n");
    } else {
        printf("You guessed it right!\n");
    }

    return 0;
}

2. Unrestricted Random Number Range #

rand() spits out a number from 0 to RAND_MAX (usually 32767). If you don't narrow it down to a reasonable range (like 1-100), your user's guess will almost never match. Use this formula to set your target:
int target = rand() % [upper_limit] + [lower_limit];
For example, rand() % 50 + 1 gives numbers from 1 to 50.

3. Incorrect Input Reading #

If you're using the wrong format specifier in scanf, the guess value will be garbage (uninitialized), leading to wrong comparisons. Always match the specifier to your variable type:

• For int: Use %d and pass the address with & (like scanf("%d", &user_guess);)
• Avoid using char for numeric guesses—they can't hold multi-digit numbers!

4. Broken Comparison Logic #

Double-check your if/else blocks to make sure you're not mixing up the conditions. For example, accidentally writing if (target > user_guess) when you mean to check the other way around would flip your feedback, but if all guesses are wrong, this is less likely than the type mismatch.

• Swap any char variables for int where you're storing numbers (target or guess)
• Add the range restriction to your rand() call
• Verify your scanf uses %d and includes the & before the variable name
• Test with a hardcoded target first (like int target = 42;) to see if the comparison works—if it does, the issue is with your random number setup

If you can share the full, uncut code, I can pinpoint the exact line causing the problem!

内容的提问来源于stack exchange，提问作者Red