2019年第二阶段我要变强个人训练赛第十七场

 1 #include<bits/stdc++.h>
 2 using namespace std;
 3 typedef long long ll;
 4 const ll mod=1e9+7;
 5 const int N=2e6+10;
 6 ll c[N],b[N];
 7 ll n,k,a,ans;
 8 ll quick(ll a,ll b){
 9     ll res=1;
10     while (b){
11         if (b&1){
12             res=res*a%mod;
13         }
14         a=a*a%mod;
15         b=b>>1;
16     }
17     return res;
18 }
19  
20 ll inv(ll x){
21     return quick(x,mod-2);
22 }
23  
24 int main()
25 {
26     c[0]=1;
27     scanf("%lld%lld",&n,&k);
28     for (int i=1;i<=n;i++)
29     {
30         scanf("%lld",&a);
31         b[a]++;
32         c[i]=c[i-1]*i%mod;
33     }
34     ans=c[n];
35     for (int i=0;i<=k;i++){
36         if (b[i]){
37             ans=ans*inv(c[b[i]])%mod;
38         }
39     }
40     cout<<ans<<endl;
41  
42 }

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 1 #include<bits/stdc++.h>
 2 using namespace std;
 3  
 4 long long n,a;
 5 long long ans;
 6 int main()
 7 {
 8     scanf("%lld",&n);
 9     for (int i=1;i<=n;i++)
10     {
11  
12         scanf("%lld",&a);
13         ans=ans|a;
14     }
15     cout<<ans<<endl;
16 }

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 1 #include<bits/stdc++.h>
 2  
 3 using namespace std;
 4 typedef long long ll;
 5 const int N=1e6+10;
 6 struct node
 7 {
 8     ll to,next,w;
 9 } e[N*2];
10 ll t,n,k,h[N],d[N],ans;
11 map<ll,ll>mp;
12  
13 void add(ll u,ll v,ll w)
14 {
15     t++;
16     e[t].to=v;
17     e[t].next=h[u];
18     h[u]=t;
19     e[t].w=w;
20 }
21  
22 void dfs(ll x,ll fa,ll y)
23 {
24     mp[y]++;
25     d[x]=y;
26     for (int i=h[x]; i; i=e[i].next)
27     {
28         ll v=e[i].to;
29         if (v==fa) continue;
30         dfs(v,x,y^e[i].w);
31     }
32 }
33  
34 int main()
35 {
36     scanf("%lld%lld",&n,&k);
37     for (int i=1; i<n; i++)
38     {
39         ll u,v,w;
40         scanf("%lld%lld%lld",&u,&v,&w);
41         add(u,v,w);
42         add(v,u,w);
43     }
44     dfs(1,1,0);
45  
46     for (int i=1; i<=n; i++)
47     {
48         if ((d[i]^k)==d[i])
49         {
50             ans+=mp[d[i]^k]-1;
51         }
52         else
53         {
54             ans+=mp[d[i]^k];
55         }
56     }
57     printf("%lld\n",ans/2);
58 }

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 1 #include<bits/stdc++.h>
 2 using namespace std;
 3 typedef long long ll;
 4 const ll mod=1e9+7;
 5 const int N=2e6+10;
 6 char c[N];
 7 ll n,sum1[N],sum2[N],k,a,ans=0x3f3f3f3f,pos;
 8  
 9 int main()
10 {
11     scanf("%d",&n);
12     scanf("%s",c+1);
13     for (int i=1;i<=n;i++){
14         sum1[i]=sum1[i-1]+(c[i]=='.');
15     }
16     for (int i=n;i>=1;i--){
17         sum2[i]=sum2[i+1]+(c[i]=='#');
18     }
19     for (int i=0;i<=n;i++){
20         ans=min(ans,i-sum1[i]+(n-i)-sum2[i+1]);
21     }
22     printf("%d\n",ans);
23 }

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 1 #include<bits/stdc++.h>
 2 using namespace std;
 3 typedef long long ll;
 4 const ll mod=1e9+7;
 5 const int N=2e6+10;
 6 const ll inf=0x3f3f3f3f3f3f3f3f;
 7 ll a[N],ans=inf;
 8 ll n,d,an,sum,f,aa;
 9 int main()
10 {
11     scanf("%lld",&n);
12     for (int i=1; i<=n; i++)
13     {
14         scanf("%lld",&a[i]);
15     }
16     for (int i=-1; i<=1; i++)
17     {
18         for (int j=-1; j<=1; j++)
19         {
20             a[1]=a[1]+i;
21             a[2]=a[2]+j;
22             sum=0;
23             f=0;
24             d=a[2]-a[1];
25             aa=a[2];
26             for (int k=3; k<=n; k++)
27             {
28                 an=aa+d;
29                 if (abs(an-a[k])>1)
30                 {
31                     f=1;
32                     break;
33                 }
34                 else sum+=abs(an-a[k]);
35                 aa=an;
36             }
37             a[1]=a[1]-i;
38             a[2]=a[2]-j;
39             if (f) continue;
40             ans=min(ans,sum+abs(i)+abs(j));
41         }
42     }
43     if (ans==inf) printf("-1\n");
44     else printf("%lld\n",ans);
45 }

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