Compilare: main.cpp: In function 'int main()': main.cpp:22:17: warning: format '%s' expects argument of type 'char*', but argument 2 has type 'char (*)[2000005]' [-Wformat=] scanf("%s", &s); ^ main.cpp:55:16: warning: converting to non-pointer type 'char' from NULL [-Wconversion-null] ans[++top] = NULL; ^~~~ main.cpp:18:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("balans2.in", "r", stdin); ^ main.cpp:19:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("balans2.out", "w", stdout); ^ main.cpp:21:19: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d ", &q); ^ main.cpp:22:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%s", &s); ^