计算两坐标的长度

-(void)calculateLength:(int)x1 andY1:(int)y1 andX2:(int)x2 andY2:(int)y2

{

    int length;

    length = sqrt(pow((x2 - x1),2) +pow((y2 - y1), 2) );

    NSLog(@"两点的长度为%d",length);

}