C语言-十进制十六进制转换

阳光穿透心脏的1/2处 2022-03-08 10:24 344阅读 0赞

### 目录 ###

*   *  1.Rain\_Conversion
     *  2.Gali\_Conversion

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一个朋友提到十进制数转十六进制后以字符串输出，基于此写了两段代码以供参考，其中涉及数组成员反转，指针等特别基础的用法。仅娱乐。

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## 1.Rain\_Conversion ##

#include "stdio.h" 
    #include "string.h" 
    #include "stdlib.h"
    #include "limits.h"
    #define MAX_SIZE 100
    int Conversion(long n,char *ret)
    { 
    	int remainder = 0;
    	char hex[16] = {  '0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f'  };
    	int result[MAX_SIZE];
    	int i = 0;
    	char *rets =NULL;
    	memset(result,0x0,MAX_SIZE);
    	if(n==0){ 
    		*ret = '0';
    		return 0;
    	}
    	while(n>0){ 
    		remainder = n%16;
    		result[i++] = remainder;
    		n /= 16;
    	}
    	rets = ret;
    	for(i=i-1;i>=0;i--){ 
    		*ret = hex[result[i]];
    		ret++;
    	}
    	//*ret = '\0';
    	ret = rets;
    	return 0;
    }
    int main() 
    { 
    	long a = 0;
    	char *ret = NULL;
    	ret = (char *)malloc(MAX_SIZE);
    REPEAT:
    	printf("please input num %ld - %ld\n",LONG_MIN,LONG_MAX);
    	if( (scanf("%ld",&a) != 1)||(a<0) ){ 
    		puts("input err");
    		goto REPEAT;
    	}
    	if( !Conversion(a,ret) ){ 
    		printf("num a = %ld,ret = 0x%s\n",a,ret);
    	}
    	free(ret);
    }

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## 2.Gali\_Conversion ##

> \------------- 代码出自咖喱鸡

#include "stdio.h"
    
    int main(void)
    { 
    	int j,re;
    	long int n;
    	int i = 0;
    	char str[100],ch;
    	puts("pleas input n(long int)");
    	scanf("%ld",&n);
    	while(n!=0){ 
    		re = n%16;
    		if( re>9 ){ 
    			str[i++] = (char)(re - 10) + 'a';
    		}else{ 
    			str[i++] = (char)re + '0';
    		}
    		n = n>>4;
    	}
    	str[i--] = '\0';
    	for(j=0;j<((i+1)>>1);j++){ 
    		ch = str[i-j];
    		str[i-j] = str[j];
    		str[j] = ch;
    	}
    	printf(" 0x%s\n",str);
    }