C语言通过下标和通过指针循环数组求平均数

#include "stdafx.h"

double getAvg(int* arr,int length);
double getAVG(int* arr,int length);
int main(int argc, char* argv[])
{
    
    

	int a[]={
    
    10,30,50,80,90};
	int length=sizeof(a)/sizeof(int);
	double res=getAVG(a,length);
	printf("%lf",res);
	return 0;
}



double getAvg(int* arr,int length){
    
    
	int sum=0;
	for(int i=0;i<length;i++){
    
    
		sum+=arr[i];
	}	
	return (double)(sum/length);
}

double getAVG(int* arr,int length){
    
    
	int sum=0;
	for(int i=0;i<length;i++){
    
    
		sum+=*arr;
		arr++;
	}
	return (double)(sum/length);
}

输出

52.000000