Compilare: main.cpp: In function 'int p1(char*)': main.cpp:17:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i(0); i < strlen(c); ++i) ~~^~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:45:15: warning: unused variable 'd' [-Wunused-variable] char *c, *d; ^ main.cpp:39:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("spion.in", "r", stdin); ^ main.cpp:40:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("spion.out", "w", stdout); ^