Compilare: user.cpp: In function ‘int main()’: user.cpp:74:31: warning: capture of variable ‘lvl’ with non-automatic storage duration [enabled by default] sort(qs + 1, qs + 1 + q, [lvl](const Q &a, const Q &b) { return (lvl[a.u] + a.h) < (lvl[b.u] + b.h); }); ^ user.cpp:15:47: note: ‘int lvl [250005]’ declared here int st[NMAX], dr[NMAX], aib[NMAX], ant[NMAX], lvl[NMAX], nbh[NMAX], val[NMAX]; ^ user.cpp:75:33: warning: capture of variable ‘lvl’ with non-automatic storage duration [enabled by default] sort(nbh + 1, nbh + 1 + n, [lvl](const int &a, const int &b) { return lvl[a] < lvl[b]; }); ^ user.cpp:15:47: note: ‘int lvl [250005]’ declared here int st[NMAX], dr[NMAX], aib[NMAX], ant[NMAX], lvl[NMAX], nbh[NMAX], val[NMAX]; ^ user.cpp: In function ‘char nextch()’: user.cpp:21:36: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff, 1, BMAX, stdin); ^ user.cpp: In function ‘int main()’: user.cpp:59:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("arb.in", "r", stdin); ^ user.cpp:60:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("arb.out", "w", stdout); ^