Compilare: main.cpp: In function 'void solve()': main.cpp:99:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 1; j < p2[i].size(); ++j) { ~~^~~~~~~~~~~~~~ main.cpp: In function 'unsigned int u32()': main.cpp:56:36: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread(buff,1,LEN,stdin); ^ main.cpp:64:36: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread(buff,1,LEN,stdin); ^ main.cpp: In function 'int main()': main.cpp:112:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("aliniate.in", "r", stdin); ^ main.cpp:113:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("aliniate.out", "w", stdout); ^