Good code. There's a little error at the end, in " return 0; ". Here I correctet some little errors.
void setup () {
int main(void);
int t,f;
unsigned int line,col;
int i,j,flag,isEven;
scanf("%d",&t);
for(f=1;f<=t;f++){
scanf("%u",&line);
scanf("%u",&col);
if(line == col)
isEven = 1;
else
isEven = 0;
flag=0;
for(i=0;i<line;i++){
for(j=0;j<col;j++){
if(flag == 0){
printf("*");
flag = 1;
}
else{
printf(".");
flag = 0;
}
}
printf("\n");
if(isEven == 1){
if(flag == 0)
flag =1;
else
flag =0;
}
}
printf("\n");
}
}
return 0;