暴力枚举+贪心
1 #include<cstdio> 2 #include<iostream> 3 #include<cstring> 4 #include<cstdlib> 5 #include<algorithm> 6 #include<queue> 7 #include<map> 8 #include<cmath> 9 #define M 100009 10 #define ll long long 11 #define Mo 998244353 12 #define pa pair<int,int> 13 using namespace std; 14 ll read() 15 { 16 char ch=getchar(); 17 ll x=0,f=1; 18 for(;ch<'0'||ch>'9';ch=getchar()) 19 if(ch=='-') 20 f=-1; 21 for(;ch>='0'&&ch<='9';ch=getchar()) 22 x=x*10+ch-'0'; 23 return x*f; 24 } 25 int a[M],shu[M],n,m,ans[M]; 26 bool pan() 27 { 28 for(int i=1;i<=n;i++) 29 a[i]=shu[i]; 30 for(int i=1;i<=n-2;i++) 31 { 32 if(a[i]<0) 33 return 0; 34 a[i]=a[i]%3; 35 a[i+1]-=a[i]; 36 a[i+2]-=a[i]; 37 } 38 if(a[n-1]%3||a[n]%3) 39 return 0; 40 return 1; 41 } 42 int main() 43 { 44 n=read(); 45 m=read(); 46 for(int i=1;i<=3*m+1;i++) 47 { 48 int a1=read(); 49 shu[a1]++; 50 } 51 for(int i=1;i<=n;i++) 52 { 53 shu[i]++; 54 for(int j=1;j<=n;j++) 55 { 56 if(shu[j]<2) 57 continue; 58 shu[j]-=2; 59 if(pan()) 60 { 61 ans[++ans[0]]=i; 62 shu[j]+=2; 63 break; 64 } 65 shu[j]+=2; 66 } 67 shu[i]--; 68 } 69 for(int i=1;i<ans[0];i++) 70 printf("%d ",ans[i]); 71 if(!ans[0]) 72 printf("NO "); 73 else 74 printf("%d ",ans[ans[0]]); 75 return 0; 76 }