Compilare: user.cpp: In function ‘void solve1()’: user.cpp:130:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<b.size();++i) ^ user.cpp: In function ‘int main()’: user.cpp:157:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("casa.in","r",stdin); ^ user.cpp:158:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("casa.out","w",stdout); ^ user.cpp:160:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&cerinta); ^ user.cpp: In function ‘void solve1()’: user.cpp:106:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:112:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %c\n",&nr,&c); ^ user.cpp: In function ‘void solve2()’: user.cpp:30:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:38:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&X); ^