/*
* Calculate number of ways to place checkers
* on each row of the board starting at row i and going to row n.
*/
void
nway(i, lim) {
int j;
if(i == n) {
nsol++;
if (n > 6 && row[0] < n/2) nsol++;
if (nprinted++ < 3) solution();
return;
}
for(j=0; j<lim; j++){
if(!col[j] && !updiag[i+j] && !downdiag[i-j+MAXN]){
row[i] = j;
col[j]++;
updiag[i+j]++;
downdiag[i-j+MAXN]++;
nway(i+1,n);
col[j]--;
updiag[i+j]--;
downdiag[i-j+MAXN]--;
}
}
}
// Check that NWayCanvas does NOT try to manage the lifetime of its sub-canvases
DEF_TEST(NWayCanvas, r) {
const int w = 10;
const int h = 10;
bool life[2];
{
LifeLineCanvas c0(w, h, &life[0]);
REPORTER_ASSERT(r, life[0]);
}
REPORTER_ASSERT(r, !life[0]);
std::unique_ptr<SkCanvas> c0 = std::unique_ptr<SkCanvas>(new LifeLineCanvas(w, h, &life[0]));
std::unique_ptr<SkCanvas> c1 = std::unique_ptr<SkCanvas>(new LifeLineCanvas(w, h, &life[1]));
REPORTER_ASSERT(r, life[0]);
REPORTER_ASSERT(r, life[1]);
{
SkNWayCanvas nway(w, h);
nway.addCanvas(c0.get());
nway.addCanvas(c1.get());
REPORTER_ASSERT(r, life[0]);
REPORTER_ASSERT(r, life[1]);
}
// Now assert that the death of the nway has NOT also killed the sub-canvases
REPORTER_ASSERT(r, life[0]);
REPORTER_ASSERT(r, life[1]);
}
main(void) {
FILE *fin = fopen("checker.in", "r");
fout = fopen("checker.out", "w");
fscanf(stdin, "%d", &n);
nway(0, n>6?(n+1)/2:n);
fprintf(fout, "%d\n", nsol);
exit (0);
}
