Compilare: main.cpp: In function 'int main()': main.cpp:8:11: warning: unused variable 'm' [-Wunused-variable] int n,m,i,j,k; ^ main.cpp:10:10: warning: unused variable 'ch1' [-Wunused-variable] char ch1,ch2; ^~~ main.cpp:10:14: warning: unused variable 'ch2' [-Wunused-variable] char ch1,ch2; ^~~ main.cpp:6:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("compact.in","r",stdin); ^ main.cpp:7:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("compact.out","w",stdout); ^ main.cpp:11:19: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ main.cpp:13:26: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&v[i]); ^