1103.Integer Factorization (30)...to be continued...

1103.Integer Factorization (30)…to be continued…

pat-al-1103

2017-03-02

• dfs
• 要记录的数据有点多，要细心

/** * pat-al-1103 * 2017-03-02 * Cpp version * Author: fengLian_s */#include<stdio.h>#include<vector>using namespace std;int n, k, p, maxFacSum = -1;vector<int> fac, ans, tmp;int power(int x){  int ans = 1;  for(int i = 0;i < p;i++)  {    ans *= x;  }  return ans;}void init(){  int i = 0, tmp = 0;  while(tmp <= n)  {    fac.push_back(tmp);    tmp = power(++i);  }}void dfs(int index, int nowK, int sum, int facSum){  if(nowK == k && sum == n)  {    if(facSum > maxFacSum)    {      ans = tmp;      maxFacSum = facSum;    }    return;  }  if(nowK > k || sum > n)    return;  if(index > 0)  {    tmp.push_back(index);    dfs(index, nowK+1, sum+fac[index], facSum+index);    tmp.pop_back();    dfs(index-1, nowK, sum, facSum);  }}int main(){  freopen("in.txt", "r", stdin);  scanf("%d%d%d", &n, &k, &p);  init();  dfs(fac.size()-1, 0, 0, 0);  if(maxFacSum == -1)    printf("Impossible");  else  {    printf("%d = %d^%d", n, ans[0], p);    for(int i = 1;i < ans.size();i++)      printf(" + %d^%d", ans[i], p);  }  putchar('\n');  return 0;}

-TBC-