View Compilation Error

0_0_18679539_1139.cpp: In function 'void cal_all_len()':
0_0_18679539_1139.cpp:32:37: error: 'callen' was not declared in this scope
       len[i] = callen(p[i], p[i + 1]);
                                     ^
0_0_18679539_1139.cpp:33:40: error: 'callen' was not declared in this scope
      len[n - 1] = callen(p[0], p[n - 1]);
                                        ^
0_0_18679539_1139.cpp: In function 'void print(double)':
0_0_18679539_1139.cpp:49:38: error: 'x' was not declared in this scope
              printf("%.2f\n", f[i] - x);
                                      ^
0_0_18679539_1139.cpp:51:38: error: 'x' was not declared in this scope
              printf("%.2f\n", f[i] + x);
                                      ^
0_0_18679539_1139.cpp: In function 'int main()':
0_0_18679539_1139.cpp:83:20: error: 'min' was not declared in this scope
             if(x < min - eps || x > max + eps)
                    ^
0_0_18679539_1139.cpp:83:37: error: 'max' was not declared in this scope
             if(x < min - eps || x > max + eps)
                                     ^