Compilare: main.cpp: In function 'int solve(int, int)': main.cpp:13:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (isalnum(s[p]) == 0 && p < strlen(s)) { ~~^~~~~~~~~~~ main.cpp:17:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (isalnum(s[p]) > 0 && p < strlen(s)) { ~~^~~~~~~~~~~ main.cpp:30:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (s[p] != ')' && p < strlen(s)) { ~~^~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:42:9: warning: unused variable 'sol' [-Wunused-variable] int sol = solve(0, 0); ^~~ main.cpp:39:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("dir.in", "r", stdin); ^ main.cpp:40:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("dir.out", "w", stdout); ^