HDU 1455 sticks

Http://acm.hdu.edu.cn/showproblem.php? PID = 1, 1455

The question is: there are a pile of wooden sticks with different lengths. They are made up of neat wooden sticks, and the minimum length is required.

Well, the first time this question was done was the day before the training. At that time, I silently used one of the few algorithms I had learned: greedy. There is no unexpected wa.

Stopped.

After 10 days, I suddenly went back to the question and thought I could use the search I learned over the past few days. Then, I knocked on a DFS and Wa. At that time, I felt that I was doing the right thing. Then I went to ask the team leader. The team leader asked me to compare the AC code data, result. I found my own mistake. Alas, I am not familiar with DFS. I forgot to recover vis.

The second DFS question in my life

Bytes

#include <cstdio>#include <cstring>#include <cstdlib>#include <algorithm>using namespace std;typedef long long LL;#define MIN(a,b) (a > b ? b : a)int N,cnt,flag,V,ok;int aa[100],ans[100],vis[100];int cmp(int a,int b){      return a > b ;}int get(int x){      int c = 0;      for (int i=1;i<=x;i++)            if (x % i == 0)ans[c++] = i;      return c;}void show(){      for (int i=0;i<N;i++)            printf("%d ",aa[i]);      printf("\n");}void DFS(int v,int t,int sum){      if (sum == 0){flag = 1;return ;}      for (int i=t;i<N && !flag;i++)      {            if (v - aa[i] >= 0 && vis[i] == 0)            {                  vis[i] = 1;                  if (v == aa[i])DFS(V,0,sum-aa[i]);                  else DFS(v-aa[i],i+1,sum-aa[i]);                  vis[i] = 0;                  if (v == aa[i] || v == V)return ;                  while (aa[i] == aa[i+1])i++;            }      }}int main(){      int cc = 1;      while (scanf("%d",&N) && N)      {            int sum = 0;            memset(aa,0,sizeof(aa));            for (int i=0;i<N;i++)            {                  scanf("%d",&aa[i]);                  sum += aa[i];            }            int m = get(sum);            sort(aa,aa+N,cmp);           // show();            for (int i=0;i<m;i++)            {                  if (aa[0] > ans[i])continue ;                  memset(vis,0,sizeof(vis));                  V = ans[i];                  flag = 0;                  DFS(ans[i],0,sum);                  if (flag )                  {                        printf("%d\n",ans[i]);                        break ;                  }            }      }      return 0;}