double calc_dist(std::vector<tLineSegment<point>> &L,size_t i, size_t j)
{
/* static std::unordered_map<size_t,double> cache; //@REMARK: magic statics are not thread-safe at Microsoft
std::unordered_map<size_t,double>::const_iterator it;
it = cache.find(key);
if (it != cache.end())
{
return (*it).second;
}*/
//@TODO: refactor
#define li1 L[i].s
#define li2 L[i].e
#define lj1 L[j].s
#define lj2 L[j].e
double len_i = d_euc(li1,li2);
double len_j = d_euc(lj1,lj2);
// total_dist: larger segement first.
double td =
(len_i >= len_j)?total_dist(li1,li2,lj1,lj2):total_dist(lj1,lj2,li1,li2);
/*if (cache.size() < 256E3/4)
cache.insert(std::pair<size_t, double>(key, td));*/
return td;
}
void dfs(int step, int city) { // city is the current city for step, i.e. the starting point of this step
//II("step = %d, city = %d", step, city);
dfs_cnt++;
int i;
ans[0][step] = city;
use[city] = 1;
int low_bound = bound(step);
if (low_bound >= best) { // bound
use[city] = 0;
return;
}
if (step == n - 1) {
int total = total_dist(ans[0]);
//fprintf(stderr, "total = %d\n", total);
if (!best || best > total) {
best = total;
memcpy(ans[1], ans[0], n * sizeof(int));
}
} else {
for (i = 1; i < n; i++) { // 0 is the city of itself
if (low_bound < 0 && best > 0) {
low_bound = bound(step);
}
if (low_bound >= best) {
break;
}
if (!use[d[2][city][i]]) {
dfs(step + 1, d[2][city][i]); // branch
}
}
}
use[city] = 0;
}
void output() {
printf("%d\n", total_dist(ans[1]));
for (i = 0; i < n; i++) {
printf("%d ", ans[1][i] + 1);
}
printf("1 \n");
}
void perm_sub(int n,int lst[]){
int i;
if(n==LENGTH){
double dist = total_dist(lst);
if(dist<sum){
sum = dist;
copy_solution(lst);
}
}else{
for(i=1;i<LENGTH;i++){
if(!(apper(lst,i,num))){
if(n!=2 || lst[0]>i){
append(lst,i,num);
num++;
perm_sub(n+1,lst);
num--;
}
}
}
}
}
