Compilare: main.cpp: In function 'int main()': main.cpp:21:29: warning: unused variable 'cnt' [-Wunused-variable] int cnt=a[j].size(); ^~~ main.cpp:10:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("balbaiala.in","r",stdin); ^ main.cpp:11:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("balbaiala.out","w",stdout); ^ main.cpp:12:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d\n",&n,&k); ^ main.cpp:13:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%s",s); ^ main.cpp:34:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%s",v); ^