题解：最长上升子序列的应用，按w升序,s降序排列后进行DP找最长序列,用pre[]数组记录该点的前驱,从而打印路径

#include 
     
        #include 
      
         using namespace std;  struct mouse{      int w,s,id;      bool operator<(const mouse& m)     const{          return w
       
        m.s);        }     }m[1005];  int d[1005],pre[1005],ms=1,ans[1005];  void solve(){      d[0]=-1;      int head=0;      for(int i=1;i<=ms;i++){          int t=0;          for(int j=1;j
        
         m[j].w&&m[i].s
         
          d[t]+1){                  t=j;              }             }          if(t==0)d[i]=1,pre[i]=-1;          else{              d[i]=d[t]+1;              pre[i]=t;          }          if(d[i]>d[head])head=i;       }           int as=0;      while(head!=-1){          ans[as++]=m[head].id;          head=pre[head];         }      printf("%d\n",as);      for(int i=as-1;i>=0;i--)printf("%d\n",ans[i]);  }  int main(){      while(scanf("%d%d",&m[ms].w,&m[ms].s)!=EOF)m[ms].id=ms,ms++;      sort(m+1,m+ms+1);            solve();      return 0;     }