十进制转九进制c语言代码

在C语言中，将十进制数转换成九进制可以采用循环和除法的方式实现。以下是一个简单的示例代码：

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

// Function to convert decimal to octal
char* decimal_to_octal(int num) {
    char result[50]; // Array to store the octal number as string
    int i = 0;
    
    if (num == 0)
        return "0"; // If input is zero, return '0'

    while(num > 0) {
        result[i++] = (num % 8) + '0'; // Convert remainder to character and append
        num /= 8; // Divide by 8 for next iteration
    }

    result[i] = '\0'; // Add null terminator

    // Reverse the string as octal representation starts from rightmost digit
    reverse(result, i);

    return result;
}

// Helper function to reverse a string in-place
void reverse(char* str, int len) {
    int start = 0;
    int end = len - 1;

    while(start < end) {
        char temp = str[start];
        str[start] = str[end];
        str[end] = temp;
        start++;
        end--;
    }
}

int main() {
    int decimal_num;
    printf("Enter a decimal number: ");
    scanf("%d", &decimal_num);
    char* octal_num = decimal_to_octal(decimal_num);
    printf("Octal equivalent of %d is: %s\n", decimal_num, octal_num);
    free(octal_num); // Don't forget to free dynamically allocated memory
    return 0;
}

在这个程序中，`decimal_to_octal`函数负责将输入的十进制数字转换为八进制字符串，然后主函数中获取用户输入并打印结果。