Problem 492. Construct the Rectangle

本文针对LeetCode上的一道题目——构造矩形进行了详细的解答。输入为矩形面积,输出为满足特定条件的矩形长宽比。文章分享了一种通过遍历宽度变量并计算长度,进而找到差值绝对值最小的解决方案。

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题目地址:https://leetcode.com/problems/construct-the-rectangle/#/description
简单理解:

input: area 表示矩形的面积
output: [L W],矩形的长和宽,其满足以下条件:
         1. L >= W
         2. L 和 W差的绝对值尽可能小

我的解法:
1. 使W从1增加到sqrt(area),在这个过程中计算L以及他们之间差的绝对值.然后和上一次循环的差对比,最终得到最小差对应的L和W。代码如下:

class Solution {
public:
    vector<int> constructRectangle(int area) {
        int maxIn = area;
        int L=0,W=0;
        for(int i = 1;i<=sqrt(area);i++){
            if(double(area*1.0/i) -area/i > 0){}
            else{
                if(abs(i - area/i)<maxIn){
                    W = i;
                    L = area/i;
                    maxIn = abs(i - area/i);
                }
            }
        }
        return vector<int>{L,W};
    }
};
# Find Rects Example # # This example shows off how to find rectangles in the image using the quad threshold # detection code from our April Tags code. The quad threshold detection algorithm # detects rectangles in an extremely robust way and is much better than Hough # Transform based methods. For example, it can still detect rectangles even when lens # distortion causes those rectangles to look bent. Rounded rectangles are no problem! # (But, given this the code will also detect small radius circles too)... import time, os, gc, sys from media.sensor import * from media.display import * from media.media import * from machine import UART import time from machine import PWM, FPIOA #servo def find_majority_element(nums): """ 查找数组中出现次数超过一半的元素(众数) 参数: nums (list): 整数数组 返回: int or None: 众数(如果存在),否则返回None """ candidate = None # 候选众数 count = 0 # 计数器 # 第一轮遍历:找出候选众数 for num in nums: if count == 0: candidate = num # 当计数器为0时,更新候选众数 count += (1 if num == candidate else -1) # 相同则加1,不同则减1 # 验证候选众数是否确实超过半数 count = 0 for num in nums: if num == candidate: count += 1 # 如果出现次数超过数组长度的一半,则返回候选众数 return candidate if count > len(nums) // 2 else None #pid class PID: def __init__(self, kp, ki, input_value, target=320): self.e = 0 self.e_last = 0 self.kp = kp self.ki = ki self.target = target self.input_value = input_value def cal(self, value): self.e = self.target - value delta = self.kp * (self.e-self.e_last) + self.ki * self.e self.e_last = self.e self.input_value = self.input_value + delta return self.input_value c_x=160 c_y=120 pid_x = PID(-0.002, -0.0003, 1.5/20*100, c_x) # 垂直控制PID: 比例系数-0.002, 积分系数-0.0003, 初始控制值1.5ms pid_y = PID(-0.002, -0.0003, 0.5/20*100, c_y) #image DETECT_WIDTH = ALIGN_UP(320, 16) DETECT_HEIGHT = 240 sensor = None color_threshold =(71, 100, -15, 15, -34, -3) #color_threshold =((97, 100, -14, -4, -45, -2)) def camera_init(): global sensor # construct a Sensor object with default configure sensor = Sensor(width=DETECT_WIDTH,height=DETECT_HEIGHT) # sensor reset sensor.reset() # set hmirror # sensor.set_hmirror(False) # sensor vflip # sensor.set_vflip(False) # set chn0 output size sensor.set_framesize(width=DETECT_WIDTH,height=DETECT_HEIGHT) # set chn0 output format sensor.set_pixformat(Sensor.RGB565) # use IDE as display output Display.init(Display.VIRT, width= DETECT_WIDTH, height = DETECT_HEIGHT,fps=100,to_ide = True) # init media manager MediaManager.init() # sensor start run sensor.run() #######################image_function def camera_deinit(): global sensor # sensor stop run sensor.stop() # deinit display Display.deinit() # sleep os.exitpoint(os.EXITPOINT_ENABLE_SLEEP) time.sleep_ms(100) # release media buffer MediaManager.deinit() def find_min_b(blobs): min_size=1000000 for blob in blobs: if min_size > blob[2]*blob[3] : min_blob=blob min_size = blob[2]*blob[3] return min_blob def find_max_c(circles): max_size=0 for circle in circles: if circle[3] > max_size: max_circle=circle max_size = circle[3] return max_circle def find_max_r(rects): max_size=0 for rect in rects: if rect[2]*rect[3] > max_size: max_rect=rect max_size = rect[2]*rect[3] return max_rect #############################servo_function def pwm_init(): pwm_io1 = FPIOA() pwm_io1.set_function(47, FPIOA.PWM3) pwm_shang = PWM(3, 50, 50, enable=True) # 配置PWM3,默认频率50Hz,占空比50%,xia # 配置排针引脚号32,芯片引脚号为46的排针复用为PWM通道2输出 pwm_io2 = FPIOA() pwm_io2.set_function(46, FPIOA.PWM2) pwm_xia = PWM(2, 50, 50, enable=True) # 配置PWM2,默认频率50Hz,占空比50%,shang pwm_xia.duty(7.5) #xia舵机旋转到中间 pwm_shang.duty(2.5) #shang舵机旋转到中间 def capture_picture(): os.exitpoint() global sensor img = sensor.snapshot() # `threshold` below should be set to a high enough value to filter out noise # rectangles detected in the image which have low edge magnitudes. Rectangles # have larger edge magnitudes the larger and more contrasty they are... for c in img.find_circles(threshold = 10000): #img.draw_circle([v for v in r.circle()], color = (255, 0, 0)) img.draw_circle(c.x(), c.y(), c.r(), color=(255,0,0)) #for p in r.corners(): img.draw_circle(p[0], p[1], 5, color = (0, 255, 0)) img.draw_cross(c.x(), c.y(),color = (255, 0, 0)) print(c) #for r in img.find_rects(threshold = 10000): # img.draw_rectangle([v for v in r.rect()], color = (255, 255, 255)) # #for p in r.corners(): img.draw_circle(p[0], p[1], 5, color = (0, 255, 0)) # print(r) #img_rect = img.to_grayscale(copy=True) #img_rect = img_rect.binary([(23, 62)]) #rects=img_rect.find_rects(threshold =2000) blobs=None global flag #global max_blob global max_rect_ #max_blob=None #max_rect_=None #if rects: # max_rect_= find_max_r(rects) # img.draw_rectangle([v for v in max_rect_.rect()], color = (255, 255, 255)) # blobs = img.find_blobs([color_threshold],roi=max_rect_.rect(),merge=True,pixels_threshold=2,area_threshold=2) for i in range(6): img_rect = img.to_grayscale(copy=True) img_rect = img_rect.binary([(23, 62)]) rects = img_rect.find_rects(threshold=10000) # 最小面积阈值10000像 # 绘制找到的矩形 if not rects == None: for rect in rects: corner = rect.corners() # 获取矩形四个角点 # 绘制矩形边界 img.draw_line(corner[0][0], corner[0][1], corner[1][0], corner[1][1], color=(0, 255, 0), thickness=1) img.draw_line(corner[2][0], corner[2][1], corner[1][0], corner[1][1], color=(0, 255, 0), thickness=1) img.draw_line(corner[2][0], corner[2][1], corner[3][0], corner[3][1], color=(0, 255, 0), thickness=1) img.draw_line(corner[0][0], corner[0][1], corner[3][0], corner[3][1], color=(0, 255, 0), thickness=1) # 计算矩形中心点 c_x = sum([corner[k][0] for k in range(4)])/4 c_y = sum([corner[k][1] for k in range(4)])/4 if len(rects) == 2: print("center_point: {}".format([round(c_x), round(c_y)])) flag = 1 # 进入追踪模式 pid_x.target = c_x pid_y.target = c_y max_rect_= find_max_r(rects) t=0 t=t+1 blobs = img.find_blobs([color_threshold],roi=max_rect_.rect(),merge=True,pixels_threshold=2,area_threshold=2) #else flag=0 if blobs: max_blob = find_min_b(blobs)#调用函数,返回最大色块 #img.draw_circle(80,60,5,color=200) img.draw_circle(max_blob.cx(),max_blob.cy(),10,color=200) img.draw_rectangle((max_blob.x(),max_blob.y(),max_blob.w(),max_blob.h()),color=(255,0,0))#用红色框出最大色块 img.draw_string_advanced(0,0, "(x,y) =") img.draw_string_advanced(max_blob.x()+40,max_blob.y(), str(max_blob.cx())) img.draw_string_advanced(max_blob.x()+60,max_blob.y(), str(max_blob.cy()))#在框图显示色块的中心坐标 img.draw_string_advanced(40,0, str(max_blob.cx())) img.draw_string_advanced(60,0, str(max_blob.cy()))#在框图左上角显示色块的中心坐标 c_x = max_blob.x() + max_blob.w() / 2 c_y = max_blob.y() + max_blob.h() / 2 new_duty = pid_x.cal(c_x) # 计算新占空比 # 限制占空比在0.5ms-2.5ms范围内(舵机安全范围) new_duty = max(min(new_duty, 2.5/20*100), 0.5/20*100) # 更新水平舵机位置 pwm_xia.enable(0) # 临时禁用PWM pwm_xia.duty(round(new_duty, 2)) # 设置新占空比 pwm_xia.enable(1) # 重新启用PWM # 垂直方向PID控制 new_duty = pid_y.cal(c_y) # 计算新占空比 # 限制占空比在安全范围内 new_duty = max(min(new_duty, 2.5/20*100), 0.5/20*100) # 更新垂直舵机位置 pwm_shang.enable(0) # 临时禁用PWM pwm_shang.duty(round(new_duty, 2)) # 设置新占空比 print(round(new_duty, 1)) # 调试输出 pwm_shang.enable(1) # 重新启用PWM # draw result to screen Display.show_image(img) img = None gc.collect() def main(): os.exitpoint(os.EXITPOINT_ENABLE) camera_is_init = False fps = time.clock() pwm_init() try: print("camera init") camera_init() camera_is_init = True print("camera capture") while True: fps.tick() try: capture_picture() except KeyboardInterrupt as e: print("user stop: ", e) break except BaseException as e: print(f"Exception {e}") break print(fps.fps()) except Exception as e: print(f"Exception {e}") finally: if camera_is_init: print("camera deinit") camera_deinit() if __name__ == "__main__": main() 这段代码报错Exception Not enough positional arguments!
最新发布
08-01
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