int
expr(void)
{
ExprNptr = ExprNstack;
ExprOptr = ExprOstack;
ExprError = FALSE;
ExprPeek = -1;
return(valof(END));
}
int solve(int rows,int cols, int cur, int tar, int x, int y)
{
int i;
if(rows==1 && cols==1)
return valof(x+1,y+1);
for(i=1;i<cols;i++)
{
cur++;
if(cur == tar)
return valof(x+1,y+i);
}
for(i=1;i<rows;i++)
{
cur++;
if(cur == tar)
return valof(x+i,y+cols);
}
for(i=cols;i>1;i--)
{
cur++;
if(cur == tar)
return valof(x+rows,y+i);
}
for(i=rows;i>1;i--)
{
cur++;
if(cur == tar)
return valof(x+i,y+1);
}
return solve(rows-2,cols-2,cur, tar, x+1,y+1);
}
int
exprfind(void)
{
register int result;
register int c;
c = exprgch();
switch(c) {
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
return(numberget(c));
case '!':
result = exprfind();
return(ExprError ? 0 : (result <= 0));
case '-':
result = exprfind();
return(ExprError ? 0 : -result);
case '(':
return(valof(RIGHTP));
case ' ':
case '\n':
case '\t':
case '\0':
printf("Expression expected: end of expression found.\n");
ExprError = TRUE;
return(0);
default:
printf("Expression expected; '%c' found: Assumed zero.\n", c);
ExprError = TRUE;
return(0);
}
}
