Compilare: user.cpp: In function ‘void add_leaves()’: user.cpp:65:16: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if (edge[i][j]) ^ user.cpp: In function ‘int main()’: user.cpp:112:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("tree2.in","r",stdin); ^ user.cpp:113:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("tree2.out","w",stdout); ^ user.cpp:115:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:117:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^