Compilare: user.cpp: In function ‘void solve()’: user.cpp:52:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < v.size(); ++ i) ^ user.cpp: In function ‘void read()’: user.cpp:22:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("calcul.in", "r", stdin); ^ user.cpp:24:27: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(s1, maxN, stdin); ^ user.cpp:26:27: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(s2, maxN, stdin); ^ user.cpp:28:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &c); ^ user.cpp: In function ‘void write()’: user.cpp:62:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("calcul.out", "w", stdout); ^