joi2019_ho_t4.cpp: In function 'int main()':
joi2019_ho_t4.cpp:10:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d", &n);
~~~~~^~~~~~~~~~
joi2019_ho_t4.cpp:11:69: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
for (int i = 1; i <= (n << 1); ++i) scanf("%d %d", x + i, y + i), z[i] = (i + 1) / 2;
~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~