2014西安网络赛
A. Post Robot
把每种单词都kmp跑一遍,顺序输出即可
#include <cstdio>
#include <iostream>
#include <algorithm>
#include <map>
#include <cstring>
#include <cmath>
#include <queue>
#include <set>
#include <vector>
#include <iterator>
#include <string>
#include <deque>
#define rep(i,a,b) for(int i=a;i<=b;++i)
#define per(i,a,b) for(int i=a;i>=b;--i)
#define pb push_back
#define MP make_pair
#define fr first
#define sc second
#define PII pair<int,int>
#define VI vector<int>
typedef long long ll;
typedef unsigned long long ull;inline int read() {char c=getchar();int x=0,f=1;while(!isdigit(c)){if(f=='-')f=-1;c=getchar();}while(isdigit(c)){x=x*10+c-'0';c=getchar();}return x*f;
}
const int N = 1000500;
using namespace std;int n;
string s,t,s1="Apple",s2="iPhone",s3="iPod",s4="iPad",s5="Sony";
int nxt[N],vis[N];
void kmp_pre(string s) {int i,j,m=s.size();j=nxt[0]=-1;i=0;while(i<m){while(-1!=j&&s[i]!=s[j])j=nxt[j];nxt[++i]=++j;}
}
void kmp(string s,string t,int f) {int i,j,n=s.size(),m=t.size();i=j=0;while(i<n){while(-1!=j&&s[i]!=t[j])j=nxt[j];++i;++j;if(j>=m) {//printf("%d ",i);vis[i] = f;j=nxt[j];}}
}
int main() {
// freopen("in.txt","r",stdin);
// freopen("out.txt","w",stdout);memset(vis,-1,sizeof(vis));int f=0;while(getline(cin,t)){if(f) s+=" ";f=1;s+=t;}kmp_pre(s1); kmp(s,s1,0);kmp_pre(s2); kmp(s,s2,0);kmp_pre(s3); kmp(s,s3,0);kmp_pre(s4); kmp(s,s4,0);kmp_pre(s5); kmp(s,s5,1);rep(i,1,s.size())if(vis[i]==0) puts("MAI MAI MAI!");else if(vis[i]==1) puts("SONY DAFA IS GOOD!");return 0;
}
B. Boring String Problem
后缀数组的帮我们排好序了,然后取后缀的前缀即可。严格第k小,就处理一下减去Height[i]即可去重,取前缀和,二分就可以找到严格第k小的串,然后问题就是,求一个串它在整个串中出现的最左边的位置。以当前这个串的左端点为中心,直接在Height数组里二分最左或最右的公共前缀长度恰好大于等于串长的位置,然后在这个区间询问最小的SA值即可。讲道理正解挺好想的。。。(用了两天发现自己的后缀数组板子有错,然后又发现不会二分。。。网上又找了一份大佬板子
#include <cstdio>
#include <iostream>
#include <algorithm>
#include <map>
#include <cstring>
#include <cmath>
#include <queue>
#include <set>
#include <vector>
#include <iterator>
#include <string>
#include <deque>
#define rep(i,a,b) for(int i=a;i<=b;++i)
#define per(i,a,b) for(int i=a;i>=b;--i)
#define pb push_back
#define MP make_pair
#define fr first
#define sc second
#define PII pair<int,int>
#define VI vector<int>
typedef long long ll;
typedef unsigned long long ull;
const int N = 100005;
inline int readint() {char c=getchar();int x=0,f=1;while(!isdigit(c)){if(f=='-')f=-1;c=getchar();}while(isdigit(c)){x=x*10+c-'0';c=getchar();}return x*f;
}
using namespace std;
int n;
char c[N],str[N];
int rnk[N] , SA[N] , Height[N];
int X[N] , Y[N] , sum[N];
int f[101000][20] , fm[101000][20];
bool cmp(int *r,int a,int b,int l) {return ( r[a] == r[b] && r[a+l] == r[b+l] );
}
void calc() {int l , p , *x = X , *y = Y , m = 128;rep(i,0,m) sum[i] = 0;rep(i,1,n) sum[ x[i] = c[i] ] ++;rep(i,1,m) sum[i] += sum[i-1];per(i,n,1) SA[ sum[ x[i] ]-- ] = i;for ( l = 1 , p = 1 ; l <= n ; m = p , l *= 2 ) {p = 0;rep(i,n-l+1,n) y[++p] = i;rep(i,1,n) if ( SA[i] > l ) y[++p] = SA[i] - l;rep(i,0,m) sum[i] = 0;rep(i,1,n) sum[ x[y[i]] ] ++;rep(i,1,m) sum[i] += sum[i-1];per(i,n,1) SA[ sum[ x[y[i]] ]-- ] = y[i];swap( x , y );x[SA[1]] = 1; p = 2;rep(i,2,n)x[ SA[i] ] = cmp(y,SA[i-1],SA[i],l) ? p - 1 : p++;}rep(i,1,n) rnk[SA[i]] = i;p = 0;rep(i,1,n) {if ( rnk[i] == 1 ) continue;while ( c[i+p] == c[SA[rnk[i]-1]+p] ) p ++;Height[rnk[i]] = p;if ( p ) p --;}
}
void init() {n = strlen(str);for(int i=0;i<n;++i) c[i+1] = str[i];c[n+1]=0;
}
int ST_h[N][22], ST_sa[N][22],Log[N];
void init_rmq() {Log[1] = 0;rep(i,2,n) Log[i]=Log[i>>1]+1LL;rep(i,1,n) ST_h[i][0]=Height[i], ST_sa[i][0]=SA[i];rep(j,1,20)for(int i=1;i+(1<<j-1)<=n;++i) {ST_h[i][j] = min(ST_h[i][j-1],ST_h[i+(1<<(j-1))][j-1]);ST_sa[i][j] = min(ST_sa[i][j-1],ST_sa[i+(1<<(j-1))][j-1]);}
}
int ask_h(int l,int r) {if(l==r)return ST_h[l][0];if(l>r)swap(l,r);++l;int p = Log[r-l+1];return min(ST_h[l][p],ST_h[r-(1<<p)+1][p]);
}
int ask_sa(int l,int r) {if(l>r)swap(l,r);int p = Log[r-l+1];return min(ST_sa[l][p],ST_sa[r-(1<<p)+1][p]);
}
ll s[N];int fd(int L,int len) {int l1=1,r1=L-1,ansl=L;while(l1<r1) {int mid = (l1+r1)>>1;if(ask_h(mid,L)>=len) r1=mid;else l1=mid+1;}if(ask_h(l1,L)>=len)ansl = min(ansl,l1);int l2=L+1,r2=n,ansr=L,tmp=-1;while(l2<=r2) {int mid = (l2+r2)>>1;if(ask_h(L,mid)<len) tmp=mid,r2=mid-1;else l2=mid+1;}if(tmp!=-1&&ask_h(L,tmp)<len)--tmp;else if(tmp==-1&&ask_h(L,n)>=len) tmp=n;if(tmp>=L+1&&tmp<=n&&ask_h(L,r2)>=len)ansr = max(r2,ansr);int x = ask_sa(ansl,ansr);return x;
}
void solve(ll k,int &l,int &r) {int p = lower_bound(s+1,s+1+n,k) - s;l = SA[p];int len = k - s[p-1] + Height[p];l = fd(p,len);r = l+len-1;return;
}
int main() {while(scanf(" %s",str)!=EOF) {init();calc();init_rmq();sum[0]=0;rep(i,1,n) s[i] = s[i-1] + (n-SA[i]-Height[i]+1);int q=readint();int l=0,r=0;while(q--) {ll x;scanf("%I64d",&x);x = (ll)(l^r^x) + 1LL;if(x>(ll)s[n]) {l=r=0;puts("0 0");continue;}solve(x,l,r);printf("%d %d\n",l,r);}}return 0;
}
C. Paint Pearls
先想暴力dp,\(dp[i] = min(dp[j-1]+D(j,i)^2), D(l,r):表示[l,r]区间内不同数的个数\)。长得想斜率优化,可是搞不出来。然后,发现只有区间的长度大于区间种类的平方时,才会有贡献,否则不如一个个加起来。于是枚举以i为右端点的区间包含k种数字,显然\(k^2\)不能大过i,现在就是要求以i为右端点包含k种数字,的最左边的位置,一开始写了主席树,然后二分左端点的两个log做法。tle了之后,发现可以双指针预处理pre[i][j]表示以i为右端点,包含j种元素的最远左端点,因为有个离散化,是一个log。所以预处理复杂度是\(O(n \sqrt{n} logn)\),dp是\(O(n \sqrt{n})\)的,然而还是t了。。。可能这个复杂度还是有点问题。。。还是写搓了??我再努力补。。
不优化确实会tle,学习了一些优化,换成刷表法dp,最重要优化的是当计算出的dp[i]大于等于dp[n]时break。
#include <cstdio>
#include <iostream>
#include <algorithm>
#include <map>
#include <cstring>
#include <cmath>
#include <queue>
#include <set>
#include <vector>
#include <iterator>
#include <string>
#include <deque>
#define rep(i,a,b) for(int i=a;i<=b;++i)
#define per(i,a,b) for(int i=a;i>=b;--i)
#define mem(W) memset(W,0,sizeof(W))
#define pb push_back
#define MP make_pair
#define fr first
#define sc second
#define PII pair<int,int>
#define VI vector<int>
typedef long long ll;
typedef unsigned long long ull;
const int N = 50010;
const ll inf = 1000000000000000LL;
inline int read() {char c=getchar();int x=0,f=1;while(!isdigit(c)){if(f=='-')f=-1;c=getchar();}while(isdigit(c)){x=x*10+c-'0';c=getchar();}return x*f;
}
using namespace std;
vector<ll> v;
int getid(ll x) {return lower_bound(v.begin(),v.end(),x) - v.begin() + 1;
}int n;
int a[N],b[N],A[N];
ll dp[N];
int vis[N];
int main() {while(scanf("%d",&n)!=EOF) {v.clear();rep(i,1,n)a[i]=read(),dp[i]=inf,v.pb(a[i]);sort(v.begin(),v.end());v.erase(unique(v.begin(),v.end()),v.end());for(int i=1;i<=n;++i) b[i]=getid(a[i]);dp[0]=0;rep(i,0,n-1) {int sz = 0;rep(j,i+1,n) {if(!vis[b[j]]) vis[b[j]]=1, A[++sz]=b[j];if(dp[i]+sz*sz>=dp[n]) break; //***if(sz*sz>n) break;dp[j] = min(dp[j],dp[i]+sz*sz);}rep(j,1,sz) vis[A[j]]=0;}printf("%I64d\n",dp[n]);}return 0;
}
E. Game
手推了几组,找规律的。把每一堆的大小都异或起来就星了。
#include <cstdio>
#include <algorithm>
#include <map>
#include <cstring>
#include <cmath>
#include <queue>
#include <set>
#include <vector>
#include <iterator>
#include <string>
#include <deque>
#define rep(i,a,b) for(int i=a;i<=b;++i)
#define per(i,a,b) for(int i=a;i>=b;--i)
#define pb push_back
#define MP make_pair
#define fr first
#define sc second
#define PII pair<int,int>
#define VI vector<int>
typedef long long ll;
typedef unsigned long long ull;inline int read() {char c=getchar();int x=0,f=1;while(!isdigit(c)){if(f=='-')f=-1;c=getchar();}while(isdigit(c)){x=x*10+c-'0';c=getchar();}return x*f;
}
using namespace std;int n,x;int main() {while(scanf("%d",&n)!=EOF){int ans=0;rep(i,1,n){int x=read();ans^=x;}if(!ans)puts("Lose");else puts("Win");}return 0;
}
F. Dice
直接从123456开始bfs出到每种状态的距离即可。查询时,替换下标即可。
#include <cstdio>
#include <algorithm>
#include <map>
#include <cstring>
#include <cmath>
#include <iostream>
#include <queue>
#include <set>
#include <vector>
#include <iterator>
#include <string>
#include <deque>
#define rep(i,a,b) for(int i=a;i<=b;++i)
#define per(i,a,b) for(int i=a;i>=b;--i)
#define pb push_back
#define MP make_pair
#define fr first
#define sc second
#define PII pair<int,int>
#define VI vector<int>
typedef long long ll;
typedef unsigned long long ull;
const int N = 654321 + 10;
inline int read() {char c=getchar();int x=0,f=1;while(!isdigit(c)){if(f=='-')f=-1;c=getchar();}while(isdigit(c)){x=x*10+c-'0';c=getchar();}return x*f;
}
using namespace std;
int hs(string s) {int hs = 0;for(int i=0;i<6;++i) hs = hs*10 + (s[i]-'0');return hs;
}
string t;
string fhs(int x) {t.clear();while(x) {t += (char)(x%10+'0');x/=10;}reverse(t.begin(),t.end());return t;
}
string tx,tx2;
int rt1(int x) {tx = fhs(x);tx2 = tx;tx2[2-1] = tx[3-1];tx2[4-1] = tx[2-1];tx2[1-1] = tx[4-1];tx2[3-1] = tx[1-1];return hs(tx2);
}
int rt2(int x) {tx = fhs(x);tx2 = tx;tx2[2-1] = tx[4-1];tx2[3-1] = tx[2-1];tx2[1-1] = tx[3-1];tx2[4-1] = tx[1-1];return hs(tx2);
}
int rt3(int x) {tx = fhs(x);tx2 = tx;tx2[2-1] = tx[5-1];tx2[6-1] = tx[2-1];tx2[1-1] = tx[6-1];tx2[5-1] = tx[1-1];return hs(tx2);
}
int rt4(int x) {tx = fhs(x);tx2 = tx;tx2[2-1] = tx[6-1];tx2[5-1] = tx[2-1];tx2[1-1] = tx[5-1];tx2[6-1] = tx[1-1];return hs(tx2);
}
int dis[N],vis[N];
void bfs(string s) {memset(dis,-1,sizeof(dis));memset(vis,0,sizeof(vis));int u = hs(s);dis[u] = 0;queue<int> q;q.push(u);vis[u]=1;while(!q.empty()) {int u = q.front(); q.pop();int tu = u;tu = rt1(u);if(!vis[tu]) {vis[tu] = 1;q.push(tu);dis[tu] = dis[u] + 1;}tu = rt2(u);if(!vis[tu]) {vis[tu] = 1;q.push(tu);dis[tu] = dis[u] + 1;}tu = rt3(u);if(!vis[tu]) {vis[tu] = 1;q.push(tu);dis[tu] = dis[u] + 1;}tu = rt4(u);if(!vis[tu]) {vis[tu] = 1;q.push(tu);dis[tu] = dis[u] + 1;}}
}int n,a[10],b[10];
map<int,int> c;
int main() {string s = "123456";bfs(s);while(scanf("%d%d%d%d%d%d",&a[1],&a[2],&a[3],&a[4],&a[5],&a[6])!=EOF) {scanf("%d%d%d%d%d%d",&b[1],&b[2],&b[3],&b[4],&b[5],&b[6]);c.clear();rep(i,1,6) c[a[i]] = i;int hs = 0;rep(i,1,6)hs=hs*10+c[b[i]];printf("%d\n",dis[hs]);}return 0;
}
H. Number Sequence
一开始想起一道题,觉得要从高位到低位分治贪心。然后发现过的人有点多啊。就开始找规律。。。于是顺利浪费了大量时间。。。首先发现最大值就是\(n*(n+1)\) ,而每一个值都可以用一些\(2^i-1\)组合成,于是我们从大到小贪心的把每个数都异或成\(2^i-1\)中的尽可能大的值即可
#include <cstdio>
#include <iostream>
#include <algorithm>
#include <map>
#include <cstring>
#include <cmath>
#include <queue>
#include <set>
#include <vector>
#include <iterator>
#include <string>
#include <deque>
#define rep(i,a,b) for(int i=a;i<=b;++i)
#define per(i,a,b) for(int i=a;i>=b;--i)
#define pb push_back
#define MP make_pair
#define fr first
#define sc second
#define PII pair<int,int>
#define VI vector<int>
typedef long long ll;
typedef unsigned long long ull;
const int N = 1e6 +100000;
inline int read() {char c=getchar();int x=0,f=1;while(!isdigit(c)){if(f=='-')f=-1;c=getchar();}while(isdigit(c)){x=x*10+c-'0';c=getchar();}return x*f;
}
using namespace std;
ll n;
ll a[N],b[N];
int vis[N];
void solve() {memset(vis,0,sizeof(vis));for(int i=n;i>=0;--i) {int e = 0;for(ll j=20;j>=0;--j) {e=(1<<j)-1;if(!vis[(e^i)]&&(e^i)<=n) {vis[(e^i)]=1;b[i] = (e^i);break;}}}
}
int main() {while(scanf("%lld",&n)!=EOF){rep(i,0,n)a[i]=read();solve();int f=0;printf("%lld\n",(n+1ll)*n);rep(i,0,n) {if(f)printf(" ");f=1;printf("%lld",b[a[i]]);}puts("");}return 0;
}
I. 233 Matrix
发现n非常小,m很大,于是想到矩阵快速幂,推一下就ok了
#include <cstdio>
#include <algorithm>
#include <map>
#include <cstring>
#include <cmath>
#include <queue>
#include <set>
#include <vector>
#include <iterator>
#include <string>
#include <deque>
#define rep(i,a,b) for(int i=a;i<=b;++i)
#define per(i,a,b) for(int i=a;i>=b;--i)
#define pb push_back
#define MP make_pair
#define fr first
#define sc second
#define PII pair<int,int>
#define VI vector<int>
#define rg register
typedef long long ll;
typedef unsigned long long ull;
const ll mod = 10000007;
inline int read() {char c=getchar();int x=0,f=1;while(!isdigit(c)){if(f=='-')f=-1;c=getchar();}while(isdigit(c)){x=x*10+c-'0';c=getchar();}return x*f;
}
using namespace std;
ll ans[20][20],c[20][20],d[20][20];
inline void mul(ll a[][20], ll b[][20], int n){for(rg int i=1;i<=n;++i)for(int j=1;j<=n;++j)ans[i][j]=0,c[i][j]=a[i][j],d[i][j]=b[i][j];for(rg int i=1;i<=n;++i)for(rg int k=1;k<=n;++k)if(c[i][k])for(rg int j=1;j<=n;++j)if(d[k][j]){ans[i][j] = (ans[i][j] + (c[i][k]*d[k][j]))%mod;}for(rg int i=1;i<=n;++i)for(rg int j=1;j<=n;++j)a[i][j]=ans[i][j];
}
ll E[20][20],A[20][20];
inline void mx_pow(ll A[][20],ll b,int n) {while(b) {if(b&1) mul(E,A,n);mul(A,A,n);b>>=1LL;}
}int n;
ll m,a[20];
int main() {while(scanf("%d%lld",&n,&m)!=EOF) {memset(A,0,sizeof(A));memset(E,0,sizeof(E));rep(i,1,n) a[i] = read();a[n+1] = 233; a[n+2] = 1;rep(i,1,n+2)E[i][i] = 1;rep(i,1,n)rep(j,1,i) A[i][j] = 1;rep(i,1,n)A[i][n+1]=1;A[n+1][n+1] = 10; A[n+1][n+2] = 3;A[n+2][n+2]=1;mx_pow(A,m,n+2);ll res = 0;rep(i,1,n+2) res = (res + (E[n][i]*a[i])%mod)%mod;printf("%lld\n",res);}return 0;
}