Compilare: user.cpp: In function ‘void back(std::vector<int>::iterator, int)’: user.cpp:20:9: warning: unused variable ‘nd’ [-Wunused-variable] int nd = *nod; ^~ user.cpp: In function ‘int main()’: user.cpp:29:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("count.in", "r", stdin); ^ user.cpp:30:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("count.out", "w", stdout); ^ user.cpp:32:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:35:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^ user.cpp:24:13: warning: array subscript is above array bounds [-Warray-bounds] G[nr + 1] = *nod; ~~~~~~~~^ user.cpp:24:13: warning: array subscript is above array bounds [-Warray-bounds] G[nr + 1] = *nod; ~~~~~~~~^ user.cpp:24:13: warning: array subscript is above array bounds [-Warray-bounds] G[nr + 1] = *nod; ~~~~~~~~^ user.cpp:24:13: warning: array subscript is above array bounds [-Warray-bounds] G[nr + 1] = *nod; ~~~~~~~~^ user.cpp:24:13: warning: array subscript is above array bounds [-Warray-bounds] G[nr + 1] = *nod; ~~~~~~~~^ user.cpp:24:13: warning: array subscript is above array bounds [-Warray-bounds] G[nr + 1] = *nod; ~~~~~~~~^