Compilare: user.cpp:51:40: warning: multi-character character constant [-Wmultichar] if(a[k][i] >= '0' && a[k][i] <= ' 9' && a[k][i+1] != ':' && a[k][i+2] != ':' && a[k][i-1] != ':' && a[k][i-1]!= ':'&&a[k][i] != '=' && a[k][i] !=' ') ^ user.cpp: In function ‘int Formula(int)’: user.cpp:33:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = q; i < strlen(a[k]); i++) ^ user.cpp:54:104: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(a[k][j] != '+' && a[k][j] != '-' && a[k][j] != '*' && a[k][j] !='/' && j < strlen(a[k])) ^ user.cpp:19:13: warning: unused variable ‘sum’ [-Wunused-variable] int i,j,sum,x,y,p,xi,yi,q; ^ user.cpp: In function ‘void Solve()’: user.cpp:71:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j,ok,num; ^