实现微信摇一摇部分功能

//实现微信摇一摇，找寻附近的10米的位置坐标。

#include "tool.h"

typedef struct {

  // char name[100];

  int x, y;

} POINT;

void input(POINT* p) { scanf("%d%d", &p->x, &p->y); }

void print(POINT* p) { printf("(%d,%d) ", p->x, p->y); }

double distance(POINT* p, POINT* q) {

  int dx = p->x - q->x;

  int dy = p->y - q->y;

  return sqrt(dx * dx + dy * dy);

}

#define N 10

POINT me = {N / 2, N / 2};

int inc(const void* a, const void* b) {

  POINT* pa = (POINT*)a;

  POINT* pb = (POINT*)b;

  double da = distance(pa, &me);

  double db = distance(pb, &me);

  double diff = da - db;

  if (diff > 0) return 1;

  if (diff < 0) return -1;

  return 0;

}

int main() {

  srand(time(NULL));

  POINT p[N];

  int i;

  for (i = 0; i < N; i++) {

    p[i].x = randInt(0, N);

    p[i].y = randInt(0, N);

  }

  for (i = 0; i < N; i++) print(p + i);

  qsort(p, N, sizeof(p[0]), inc);

  puts("-------------After sorted-----------");

  for (i = 0; i < N; i++) {

    printf("%.3f ", distance(p + i, &me));

    print(p + i);

  }

}