lq2.2 suma de matriz y cadena inversa

//problem：翻转字符串中，b2最后多了一串乱码 

#include <stdio.h>

#define N 5

int getsum(int a[],int start,int length);
void fanzhuan(char* b,char* b2,int start,int blength);

int main()
{
    
    
	//数组元素求和
	int a[N]={
    
    };
	int length,sum;
	length=sizeof(a)/sizeof(int);
	printf("请输入%d个数组元素：",N);
	for(int i=0;i<length;i++)
	{
    
    
		scanf("%d",&a[i]); 
	}
	sum=getsum(a,0,length);
	printf("%d\n",sum);
	//翻转字符串
	char b[]={
    
    "I love china"};
	int blength;
	blength=sizeof(b)/sizeof(char)-1;
	char b2[blength];
	printf("%s\n",b);
	fanzhuan(b,b2,0,blength);	
	printf("%s",b2);
	 
}

int getsum(int a[],int start,int length)
{
    
    
	if(start==length-1)
		return a[start];
	return a[start]+getsum(a,start+1,length);
}

void fanzhuan(char* b,char* b2,int start,int blength)
{
    
    
	b2[blength-1-start]=b[start];
	if(start!=blength-1)
		fanzhuan(b,b2,start+1,blength);
}