int islandPerimeter(vector<vector<int>>& grid) {
int perim = 0;
for(int i=0; i<grid.size(); ++i){
for(int j=0; j<grid[0].size(); ++j){
perim += getPerim(i, j, grid);
}
}
return perim;
}
int getNextInterval(TTable *curve, double y, double yLast, double wLast,
double *y1, double *y2, double *w1, double *w2,
double *wMax)
//
// Input: curve = pointer to a user-supplied shape curve table
// y = current height in a geometry table
// yLast = previous height in a geometry table
// wLast = previous width in a geometry table
// y1 = height at start of current curve interval
// y2 = height at end of current curve interval
// w1 = width at start of current curve interval
// w2 = width at end of current curve interval
// wMax = current maximum width of curve
// Output: updated values for yLast, wLast, y1, y2, w1, w2, and wMax;
// returns TRUE if successful, FALSE if not.
// Purpose: advances to the next height interval of a shape's curve that
// contains the current height being evaluated in the shape's
// geometry table.
//
// Note: heights and widths are with repsect to a shape of unit height.
{
// --- keep advancing while the current geom. table height is
// above the end of the curve table interval
while ( y > *y2 )
{
// --- move start of geom. table interval up to the end of
// the current curve table interval
if ( *y2 > yLast )
{
Atotal += getArea(*y2, *w2, yLast, wLast);
Ptotal += getPerim(*y2, *w2, yLast, wLast);
yLast = *y2;
wLast = *w2;
}
// --- move to the next curve table interval
*y1 = *y2;
*w1 = *w2;
if ( !table_getNextEntry(curve, y2, w2) )
{
*y2 = 1.0;
return TRUE;
}
// --- update curve table's max. width
if ( *w2 > *wMax ) *wMax = *w2;
// --- check for valid curve table values
if ( *y2 < *y1 || *w2 < 0.0 ) return FALSE;
if ( *y2 > 1.0 ) *y2 = 1.0;
}
return TRUE;
}
int computeShapeTables(TShape *shape, TTable *curve)
//
// Input: shape = pointer to a TShape object
// curve = pointer to shape's table of width v. depth
// Output: returns TRUE if successful. FALSE if not
// Purpose: computes the entries in a shape's geometry tables from
// the shape's width v. height curve normalized with repsect
// to full height.
//
// Note: the shape curve is a user-supplied table of width v. height
// for a custom x-section of unit height.
{
int i, n;
double dy, y, y1, y2, w, w1, w2;
double yLast, wLast, wMax;
// --- get first entry of user's shape curve
if ( !table_getFirstEntry(curve, &y1, &w1) ) return FALSE;
if ( y1 < 0.0 || y1 >= 1.0 || w1 < 0.0 ) return FALSE;
wMax = w1;
// --- if first entry not at zero ht. then add an initial entry
if ( y1 != 0.0 )
{
y2 = y1;
w2 = w1;
y1 = 0.0;
w1 = 0.0;
}
// --- otherwise get next entry in the user's shape curve
else
{
if ( !table_getNextEntry(curve, &y2, &w2) ) return FALSE;
if ( y2 < y1 || w2 < 0.0 ) return FALSE;
if ( y2 > 1.0 ) y2 = 1.0;
if ( w2 > wMax ) wMax = w2;
}
// --- determine number of entries & interval size in geom. tables
shape->nTbl = N_SHAPE_TBL;
n = shape->nTbl - 1;
dy = 1.0 / (double)(n);
// --- initialize geometry tables
shape->areaTbl[0] = 0.0;
shape->hradTbl[0] = 0.0;
shape->widthTbl[0] = w1;
Ptotal = w1;
Atotal = 0.0;
// --- fill in rest of geometry tables
y = 0.0;
w = w1;
for ( i = 1; i <= n; i++ )
{
// --- advance to next relative height level
yLast = y;
wLast = w;
y = y + dy;
// --- do not allow height to exceed 1.0
if ( fabs(y - 1.0) < TINY ) y = 1.0;
// --- if height exceeds current shape curve interval,
// move to next interval of shape curve
if ( y > y2 )
{
if ( !getNextInterval(curve, y, yLast, wLast, &y1, &y2, &w1,
&w2, &wMax) )
return FALSE;
yLast = y1;
wLast = w1;
}
// --- get top width, area, & perimeter of current interval
w = getWidth(y, y1, y2, w1, w2);
Atotal += getArea(y, w, yLast, wLast);
Ptotal += getPerim(y, w, yLast, wLast);
// --- add top width to total perimeter if at top of shape
if ( y == 1.0 ) Ptotal += w2;
// --- update table values
shape->widthTbl[i] = w;
shape->areaTbl[i] = Atotal;
if ( Ptotal > 0.0) shape->hradTbl[i] = Atotal / Ptotal;
else shape->hradTbl[i] = 0.0;
}
// --- assign values to shape'a area and hyd. radius when full
shape->aFull = shape->areaTbl[n];
shape->rFull = shape->hradTbl[n];
// --- assign values to shape's max. width and section factor
shape->wMax = wMax;
getSmax(shape);
return TRUE;
}
