Compilare: user.cpp: In function ‘int main()’: user.cpp:51:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(b[i][j]>=a[i][j]) b[i][j]-=a[i][j]; ^ user.cpp:73:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(b[i][j]>=a[i][j]) ^ user.cpp:37:39: warning: unused variable ‘val’ [-Wunused-variable] unsigned long long st=0,dr=~0,med,val,varsat=0,b[60][60],t=0; ^ user.cpp:37:62: warning: unused variable ‘t’ [-Wunused-variable] unsigned long long st=0,dr=~0,med,val,varsat=0,b[60][60],t=0; ^ user.cpp:7:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pic.in","r",stdin); ^ user.cpp:8:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pic.out","w",stdout); ^ user.cpp:10:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&v); ^ user.cpp:11:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:19:39: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&a[lin][col++]); ^