void genPerms(deque<int> & unvisited, vector<int> & path) {
if(unvisited.empty()) {
ret.push_back(path);
}
for(unsigned k = 0; k < unvisited.size(); k++) {
path.push_back(unvisited.front());
unvisited.pop_front();
genPerms(unvisited, path);
unvisited.push_back(path.back());
path.pop_back();
}
}
int main(){
int i, j, k, m;
int permutations[4*3*2] = {0};
int currDiff;
genPrimes();
for (i = 1001; i < 10000; i += 2){
if (primes[i]){
permutations[0] = i;
genPerms(permutations); /*only prime perms*/
for (j = 0; permutations[j+2] && j < (4*3*2); j++){
for (k = j+1; permutations[k+1] && k < (4*3*2); k++){
currDiff = permutations[k] - permutations[j];
for (m = k+1; permutations[m] && m < (4*3*2); m++){
if (permutations[m] == permutations[k] + currDiff){
printf("%d%d%d\n", permutations[j], permutations[k],
permutations[m]);
return 0;
}
}
}
}
for (j = 0; permutations[j] && j < 4*3*2; j++){
primes[j] = 0;
}
}
memset(permutations, 0, 4*3*2*sizeof(int));
}
return -1;
}
vector<vector<int>> permute(vector<int>& nums) {
deque<int> unvisited(nums.begin(), nums.end());
vector<int> path;
genPerms(unvisited, path);
return ret;
}
