Educational Codeforces Round 76 (Rated for Div. 2)
Educational Codeforces Round 76 (Rated for Div. 2)
思路：最多可加x个距离，且最后的距离不能超过n-1
#include<bits/stdc++.h> using namespace std; #define int long long //#define int __int128 typedef pair<int,int>PII; typedef pair<string,int>PSI; typedef pair<string,string>PSS; const int N=50+5,INF=0x3f3f3f3f,Mod=1e9+7,mod=998244353; const int inf=0x3f3f3f3f3f3f; const double eps=1e-6; const int dx[4]={-1,0,1,0}; const int dy[4]={0,1,0,-1}; void solve(){ int n,x,a,b;cin>>n>>x>>a>>b; int ans=abs(a-b); ans+=x; ans=min(n-1,ans); cout<<ans<<'\n'; } signed main(){ ios::sync_with_stdio(0),cin.tie(0),cout.tie(0); int T=1; cin>>T; while(T--){ solve(); } return 0; }
思路：x>=y时可以通过操作二完成；x<y时，当x>3时，x可以通过多次操作不断增加，直到大于y；只需要特判下x=1、2、3的情况
#include<bits/stdc++.h> using namespace std; #define int long long //#define int __int128 typedef pair<int,int>PII; typedef pair<string,int>PSI; typedef pair<string,string>PSS; const int N=50+5,INF=0x3f3f3f3f,Mod=1e9+7,mod=998244353; const int inf=0x3f3f3f3f3f3f; const double eps=1e-6; const int dx[4]={-1,0,1,0}; const int dy[4]={0,1,0,-1}; void solve(){ int x,y;cin>>x>>y; if(x>=y){ cout<<"YES\n";return ; } if(x%2)x--; if((x/2*3-1)>x||((x/2*3)==y))cout<<"YES\n"; else cout<<"NO\n"; } signed main(){ ios::sync_with_stdio(0),cin.tie(0),cout.tie(0); int T=1; cin>>T; while(T--){ solve(); } return 0; }
思路：更新每个点的位置，每次记录每个点与上一个该点的距离，取最小
/*#pragma GCC optimize(1) #pragma GCC optimize(2) #pragma GCC optimize(3) #pragma GCC optimize("Ofast") #pragma GCC optimize("inline") #pragma GCC optimize("-fgcse") #pragma GCC optimize("-fgcse-lm") #pragma GCC optimize("-fipa-sra") #pragma GCC optimize("-ftree-pre") #pragma GCC optimize("-ftree-vrp") #pragma GCC optimize("-fpeephole2") #pragma GCC optimize("-ffast-math") #pragma GCC optimize("-fsched-spec") #pragma GCC optimize("unroll-loops") #pragma GCC optimize("-falign-jumps") #pragma GCC optimize("-falign-loops") #pragma GCC optimize("-falign-labels") #pragma GCC optimize("-fdevirtualize") #pragma GCC optimize("-fcaller-saves") #pragma GCC optimize("-fcrossjumping") #pragma GCC optimize("-fthread-jumps") #pragma GCC optimize("-funroll-loops") #pragma GCC optimize("-freorder-blocks") #pragma GCC optimize("-fschedule-insns") #pragma GCC optimize("inline-functions") #pragma GCC optimize("-ftree-tail-merge") #pragma GCC optimize("-fschedule-insns2") #pragma GCC optimize("-fstrict-aliasing") #pragma GCC optimize("-falign-functions") #pragma GCC optimize("-fcse-follow-jumps") #pragma GCC optimize("-fsched-interblock") #pragma GCC optimize("-fpartial-inlining") #pragma GCC optimize("no-stack-protector") #pragma GCC optimize("-freorder-functions") #pragma GCC optimize("-findirect-inlining") #pragma GCC optimize("-fhoist-adjacent-loads") #pragma GCC optimize("-frerun-cse-after-loop") #pragma GCC optimize("inline-small-functions") #pragma GCC optimize("-finline-small-functions") #pragma GCC optimize("-ftree-switch-conversion") #pragma GCC optimize("-foptimize-sibling-calls") #pragma GCC optimize("-fexpensive-optimizations") #pragma GCC optimize("inline-functions-called-once") #pragma GCC optimize("-fdelete-null-pointer-checks")*/ #include<bits/stdc++.h> using namespace std; #define int long long //#define int __int128 typedef pair<int,int>PII; typedef pair<string,int>PSI; typedef pair<string,string>PSS; const int N=2e5+5,INF=0x3f3f3f3f,Mod=1e9+7,mod=998244353; const int inf=0x3f3f3f3f3f3f; const double eps=1e-6; const int dx[4]={-1,0,1,0}; const int dy[4]={0,1,0,-1}; vector<int>ve(N); void solve(){ int n;cin>>n; vector<int>st(n+1,0); for(int i=1;i<=n;++i)cin>>ve[i]; int ans=-1; for(int i=1;i<=n;++i){ if(st[ve[i]]){ if(ans==-1)ans=i-st[ve[i]]+1; else ans=min(ans,i-st[ve[i]]+1); } st[ve[i]]=i; } cout<<ans<<'\n'; } signed main(){ ios::sync_with_stdio(0),cin.tie(0),cout.tie(0); int T=1; cin>>T; while(T--){ solve(); } return 0; }
D - Yet Another Monster Killing Problem
思路：记录每种忍耐的最大power，依次枚举一天能杀死的最大怪兽数
#pragma GCC optimize(1) #pragma GCC optimize(2) #pragma GCC optimize(3) #pragma GCC optimize("Ofast") #pragma GCC optimize("inline") #pragma GCC optimize("-fgcse") #pragma GCC optimize("-fgcse-lm") #pragma GCC optimize("-fipa-sra") #pragma GCC optimize("-ftree-pre") #pragma GCC optimize("-ftree-vrp") #pragma GCC optimize("-fpeephole2") #pragma GCC optimize("-ffast-math") #pragma GCC optimize("-fsched-spec") #pragma GCC optimize("unroll-loops") #pragma GCC optimize("-falign-jumps") #pragma GCC optimize("-falign-loops") #pragma GCC optimize("-falign-labels") #pragma GCC optimize("-fdevirtualize") #pragma GCC optimize("-fcaller-saves") #pragma GCC optimize("-fcrossjumping") #pragma GCC optimize("-fthread-jumps") #pragma GCC optimize("-funroll-loops") #pragma GCC optimize("-freorder-blocks") #pragma GCC optimize("-fschedule-insns") #pragma GCC optimize("inline-functions") #pragma GCC optimize("-ftree-tail-merge") #pragma GCC optimize("-fschedule-insns2") #pragma GCC optimize("-fstrict-aliasing") #pragma GCC optimize("-falign-functions") #pragma GCC optimize("-fcse-follow-jumps") #pragma GCC optimize("-fsched-interblock") #pragma GCC optimize("-fpartial-inlining") #pragma GCC optimize("no-stack-protector") #pragma GCC optimize("-freorder-functions") #pragma GCC optimize("-findirect-inlining") #pragma GCC optimize("-fhoist-adjacent-loads") #pragma GCC optimize("-frerun-cse-after-loop") #pragma GCC optimize("inline-small-functions") #pragma GCC optimize("-finline-small-functions") #pragma GCC optimize("-ftree-switch-conversion") #pragma GCC optimize("-foptimize-sibling-calls") #pragma GCC optimize("-fexpensive-optimizations") #pragma GCC optimize("inline-functions-called-once") #pragma GCC optimize("-fdelete-null-pointer-checks") #include<bits/stdc++.h> using namespace std; #define int long long //#define int __int128 typedef pair<int,int>PII; typedef pair<string,int>PSI; typedef pair<string,string>PSS; const int N=2e5+5,INF=0x3f3f3f3f,Mod=1e9+7,mod=998244353; const int inf=0x3f3f3f3f3f3f; const double eps=1e-6; const int dx[4]={-1,0,1,0}; const int dy[4]={0,1,0,-1}; vector<int>cnt(N); vector<int>a(N); void solve(){ int n;cin>>n; for(int i=1;i<=n;++i){ cin>>a[i];cnt[i]=0; } cnt[0]=0; int m;cin>>m; for(int i=1,p,s;i<=m;++i){ cin>>p>>s; cnt[s]=max(cnt[s],p); } for(int i=n-1;i>=1;--i)cnt[i]=max(cnt[i+1],cnt[i]); int ans=0,now=1; while(now<=n){ ans++; int ma=0,t=now; while(1){ ma=max(ma,a[t]); if(cnt[t-now+1]<ma)break; t++; } if(now==t){cout<<"-1\n";return ;} now=t; } cout<<ans<<'\n'; } signed main(){ ios::sync_with_stdio(0),cin.tie(0),cout.tie(0); int T=1; cin>>T; while(T--){ solve(); } return 0; }
思路：
dp1：cnt[i][j]表示1~i摆放的情况，且i放在j堆的最小移动数量，（j=1、2、3）
由于三堆的序列要有序，i一定是摆在i-1的后面；再记录下1~n原来所在堆
那么cnt[i][1]=cnt[i-1][1]+1；
cnt[i][2]=min（cnt[i-1][1]，cnt[i-1][2]）+1；
cnt[i][3]=min（cnt[i-1][1]，cnt[i-1][2]，cnt[i-1][3]）+1；
减去i原来所在堆的情况；
dp2：要使三堆有序，先将一堆里数排好序，对多个数进行操作后序列一定是有序的，那么找出原序列中不变的数即可知道变的数，不变的数越多，变的数越少，即找最长上升子序列；
最长上升子序列：dp的思想，dp[i]表示以a[i]为结尾的最长上升子序列的长度，dp[i]=dp[1~（i-1）]max+1，n2的复杂度
优化下，按最长上升子序列的长度划分，记录每个长度的上升子序列最后一个数的最小值（像138，长度为1的子序列有1、3、8，找长度为2的时，8可以接在3后，也一定可以接在1后），并且随着长度增大，末尾的数也增大，因此可以二分找出可以接着的最大长度
#pragma GCC optimize(1) #pragma GCC optimize(2) #pragma GCC optimize(3) #pragma GCC optimize("Ofast") #pragma GCC optimize("inline") #pragma GCC optimize("-fgcse") #pragma GCC optimize("-fgcse-lm") #pragma GCC optimize("-fipa-sra") #pragma GCC optimize("-ftree-pre") #pragma GCC optimize("-ftree-vrp") #pragma GCC optimize("-fpeephole2") #pragma GCC optimize("-ffast-math") #pragma GCC optimize("-fsched-spec") #pragma GCC optimize("unroll-loops") #pragma GCC optimize("-falign-jumps") #pragma GCC optimize("-falign-loops") #pragma GCC optimize("-falign-labels") #pragma GCC optimize("-fdevirtualize") #pragma GCC optimize("-fcaller-saves") #pragma GCC optimize("-fcrossjumping") #pragma GCC optimize("-fthread-jumps") #pragma GCC optimize("-funroll-loops") #pragma GCC optimize("-freorder-blocks") #pragma GCC optimize("-fschedule-insns") #pragma GCC optimize("inline-functions") #pragma GCC optimize("-ftree-tail-merge") #pragma GCC optimize("-fschedule-insns2") #pragma GCC optimize("-fstrict-aliasing") #pragma GCC optimize("-falign-functions") #pragma GCC optimize("-fcse-follow-jumps") #pragma GCC optimize("-fsched-interblock") #pragma GCC optimize("-fpartial-inlining") #pragma GCC optimize("no-stack-protector") #pragma GCC optimize("-freorder-functions") #pragma GCC optimize("-findirect-inlining") #pragma GCC optimize("-fhoist-adjacent-loads") #pragma GCC optimize("-frerun-cse-after-loop") #pragma GCC optimize("inline-small-functions") #pragma GCC optimize("-finline-small-functions") #pragma GCC optimize("-ftree-switch-conversion") #pragma GCC optimize("-foptimize-sibling-calls") #pragma GCC optimize("-fexpensive-optimizations") #pragma GCC optimize("inline-functions-called-once") #pragma GCC optimize("-fdelete-null-pointer-checks") #include<bits/stdc++.h> using namespace std; #define int long long //#define int __int128 typedef pair<int,int>PII; typedef pair<string,int>PSI; typedef pair<string,string>PSS; const int N=2e5+5,INF=0x3f3f3f3f,Mod=1e9+7,mod=998244353; const int inf=0x3f3f3f3f3f3f; const double eps=1e-6; const int dx[4]={-1,0,1,0}; const int dy[4]={0,1,0,-1}; int dp[N][4]; int st[N]; void solve(){ int k[3],n=0; for(int i=0;i<3;++i)cin>>k[i],n+=k[i]; for(int i=0;i<3;++i){ for(int j=0,x;j<k[i];++j){ cin>>x; st[x]=i+1; } } dp[1][1]=dp[1][2]=dp[1][3]=1; int t=st[1]; dp[1][t]--; for(int i=2;i<=n;++i){ int t1=dp[i-1][1],t2=dp[i-1][2],t3=dp[i-1][3]; t=st[i]; dp[i][1]=t1+1; dp[i][2]=min(t1,t2)+1; dp[i][3]=min(t1,min(t2,t3))+1; dp[i][t]--; } cout<<min(dp[n][1],min(dp[n][2],dp[n][3])); } signed main(){ ios::sync_with_stdio(0),cin.tie(0),cout.tie(0); int T=1; //cin>>T; while(T--){ solve(); } return 0; }
#pragma GCC optimize(1) #pragma GCC optimize(2) #pragma GCC optimize(3) #pragma GCC optimize("Ofast") #pragma GCC optimize("inline") #pragma GCC optimize("-fgcse") #pragma GCC optimize("-fgcse-lm") #pragma GCC optimize("-fipa-sra") #pragma GCC optimize("-ftree-pre") #pragma GCC optimize("-ftree-vrp") #pragma GCC optimize("-fpeephole2") #pragma GCC optimize("-ffast-math") #pragma GCC optimize("-fsched-spec") #pragma GCC optimize("unroll-loops") #pragma GCC optimize("-falign-jumps") #pragma GCC optimize("-falign-loops") #pragma GCC optimize("-falign-labels") #pragma GCC optimize("-fdevirtualize") #pragma GCC optimize("-fcaller-saves") #pragma GCC optimize("-fcrossjumping") #pragma GCC optimize("-fthread-jumps") #pragma GCC optimize("-funroll-loops") #pragma GCC optimize("-freorder-blocks") #pragma GCC optimize("-fschedule-insns") #pragma GCC optimize("inline-functions") #pragma GCC optimize("-ftree-tail-merge") #pragma GCC optimize("-fschedule-insns2") #pragma GCC optimize("-fstrict-aliasing") #pragma GCC optimize("-falign-functions") #pragma GCC optimize("-fcse-follow-jumps") #pragma GCC optimize("-fsched-interblock") #pragma GCC optimize("-fpartial-inlining") #pragma GCC optimize("no-stack-protector") #pragma GCC optimize("-freorder-functions") #pragma GCC optimize("-findirect-inlining") #pragma GCC optimize("-fhoist-adjacent-loads") #pragma GCC optimize("-frerun-cse-after-loop") #pragma GCC optimize("inline-small-functions") #pragma GCC optimize("-finline-small-functions") #pragma GCC optimize("-ftree-switch-conversion") #pragma GCC optimize("-foptimize-sibling-calls") #pragma GCC optimize("-fexpensive-optimizations") #pragma GCC optimize("inline-functions-called-once") #pragma GCC optimize("-fdelete-null-pointer-checks") #include<bits/stdc++.h> using namespace std; #define int long long //#define int __int128 typedef pair<int,int>PII; typedef pair<string,int>PSI; typedef pair<string,string>PSS; const int N=2e5+5,INF=0x3f3f3f3f,Mod=1e9+7,mod=998244353; const int inf=0x3f3f3f3f3f3f; const double eps=1e-6; const int dx[4]={-1,0,1,0}; const int dy[4]={0,1,0,-1}; void solve(){ int k[3],n=0; for(int i=0;i<3;++i)cin>>k[i],n+=k[i]; vector<int>ve(n); for(int i=0;i<n;++i)cin>>ve[i]; sort(ve.begin(),ve.begin()+k[0]); sort(ve.begin()+k[0],ve.begin()+k[0]+k[1]); sort(ve.begin()+k[0]+k[1],ve.begin()+k[0]+k[1]+k[2]); int len=0; vector<int>q(n+2,0); q[0]=-INF; for(int i=0;i<n;++i){ int l=0,r=len,ans; while(l<=r){ int mid=l+r>>1; if(q[mid]<ve[i])ans=mid,l=mid+1; else r=mid-1; } len=max(len,ans+1); q[ans+1]=ve[i]; } cout<<n-len; } signed main(){ ios::sync_with_stdio(0),cin.tie(0),cout.tie(0); int T=1; //cin>>T; while(T--){ solve(); } return 0; }
思路：因为x的范围为[0，230-1]，所以考虑将x折半枚举，分为高位15位和低位15位；
h[i]和l[i]分别表示第i个数的高位15位和低位15位异或x后的数的1的个数，枚举两次x，对高位枚举x1，对低位枚举x2，得到每个数的高位和低位异或x后的数的1的个数；
对于一个x，高位和低位异或x后的1的个数的情况为，{ h[1]，h[2]，...，h[n] }，{ l[1]，l[2]，...，l[n] }
若x满足条件，则h[1]+l[1]=h[2]+l[2]=...=h[n]+l[n]→h[1]-h[2]= -（l[1]-l[2]）、h[1]-h[3]= -（l[1]-l[3]）、...、h[1]-h[n]= -（l[1]-l[n]）
那么用set记录每个x的{（h[1]-h[2]）、...、（h[1]-h[n]）}
同样的枚举低位时，对于当前的x1，有{（ -（l[1]-l[2]））、...、（ -（l[1]-l[n]））}，判断下set里是否存有相同的，有则说明存在一个数为x<<15+x1，满足条件
#include<bits/stdc++.h> using namespace std; #define int long long //#define int __int128 typedef pair<int,int>PII; typedef pair<string,int>PSI; typedef pair<string,string>PSS; const int N=2e5+5,INF=0x3f3f3f3f,Mod=1e9+7; const double eps=1e-6; struct E{ vector<int>ve; int x; bool operator<(const E&e)const { return ve<e.ve; } }e; vector<int>cnt(1<<15+5); void init(){ for(int i=1;i<(1<<15);++i){ int c=__builtin_popcount(i); cnt[i]=c; } } void solve(){ int n;cin>>n; vector<int>h(n),l(n); for(int i=0,x;i<n;++i){ cin>>x; h[i]=x/(1<<15),l[i]=x%(1<<15); } set<E>hh; for(int i=0;i<(1<<15);++i){ e.x=i; e.ve.clear(); int v=cnt[i^h[0]]; for(int j=1;j<n;++j) e.ve.push_back(v-cnt[i^h[j]]); hh.insert(e); } for(int i=0;i<(1<<15);++i){ e.x=i; e.ve.clear(); int v=cnt[i^l[0]]; for(int j=1;j<n;++j) e.ve.push_back(cnt[i^l[j]]-v); if(hh.find(e)!=hh.end()){ e=*hh.find(e); cout<<(e.x<<15)+i; return ; } } cout<<"-1"; } signed main(){ ios::sync_with_stdio(0),cin.tie(0),cout.tie(0); int t=1; init(); //cin>>t; while(t--){ solve(); } return 0; }
