View Compilation Error

0_0_36936868_15818.cpp:17:5: error: 'M' was not declared in this scope
 } p[M];
     ^
0_0_36936868_15818.cpp: In function 'bool cmp(int, int)':
0_0_36936868_15818.cpp:24:12: error: 'p' was not declared in this scope
     return p[a].a > p[a].b;
            ^
0_0_36936868_15818.cpp: In function 'int find(int, int)':
0_0_36936868_15818.cpp:37:29: error: 'p' was not declared in this scope
     if (deg[x] == 0 || y >= p[son[x][0]].a) return st[x];
                             ^
0_0_36936868_15818.cpp:41:13: error: 'p' was not declared in this scope
         if (p[son[x][mid]].a > y) l = mid;
             ^
0_0_36936868_15818.cpp: In function 'int main()':
0_0_36936868_15818.cpp:73:35: error: 'p' was not declared in this scope
             scanf("%d %d %d %d", &p[i].x, &p[i].y, &p[i].a, &p[i].b);
                                   ^
0_0_36936868_15818.cpp:90:31: error: 'p' was not declared in this scope
                 int  y = find(p[id].y, p[id].a);
                               ^