Compilare: user.cpp: In function ‘void build_heavy()’: user.cpp:113:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < paths.size(); i++) ~~^~~~~~~~~~~~~~ user.cpp:108:12: warning: unused variable ‘j’ [-Wunused-variable] int i, j; ^ user.cpp: In function ‘void get_vals()’: user.cpp:134:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < paths.size(); i++) { ~~^~~~~~~~~~~~~~ user.cpp:136:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j = 0; j < paths[i].size(); j++) ~~^~~~~~~~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:188:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("minmaxtree.in","r",stdin); ^ user.cpp:189:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("minmaxtree.out","w",stdout); ^ user.cpp:191:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:193:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^ user.cpp:199:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &m); ^ user.cpp:201:44: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%c%d%d%d\n", &c, &x, &y, &z); ^