牛客网暑期ACM多校训练营day2
A
#include<bits/stdc++.h>
#define inc(i,l,r) for(int i=l;i<=r;i++)
#define dec(i,l,r) for(int i=l;i>=r;i--)
#define mem(a) memset(a,0,sizeof(a))
#define sqr(x) ((x)*(x))
#define ll long long
#define lowbit(x) ((x)&(-x))
#define link(x) for(edge*j=h[x];j;j=j->next)
#define NM 100005
ll read(){
ll x=0,f=1;char ch=getchar();
while(!isdigit(ch)){if(ch=='-')f=-1;ch=getchar();}
while(isdigit(ch))x=x*10+ch-'0',ch=getchar();
return x*f;
}
const ll inf=1e9+7;
int n,k,T,_x,_y;
ll d[NM][2],c[NM];
int main(){
T=read();k=read();n=1e5;
d[0][0]=1;
inc(i,1,n){
d[i][0]+=d[i-1][0]+d[i-1][1];
if(i>=k)d[i][1]=d[i-k][0];
d[i][0]%=inf;d[i][1]%=inf;
c[i]=c[i-1]+d[i][0]+d[i][1];
c[i]%=inf;
}
// inc(i,1,5)printf("%d ",d[i][0]+d[i][1]);putchar('\n');
while(T--){
_x=read();_y=read();printf("%lld\n",(c[_y]-c[_x-1]+inf)%inf);
}
return 0;
}
B贴上队友博客
https://blog.csdn.net/qkoqhh/article/details/81193435
/**
* ┏┓ ┏┓
* ┏┛┗━━━━━━━┛┗━━━┓
* ┃ ┃
* ┃ ━ ┃
* ┃ ＞ ＜ ┃
* ┃ ┃
* ┃... ⌒ ... ┃
* ┃ ┃
* ┗━┓ ┏━┛
* ┃ ┃ Code is far away from bug with the animal protecting
* ┃ ┃ 神兽保佑,代码无bug
* ┃ ┃
* ┃ ┃
* ┃ ┃
* ┃ ┃
* ┃ ┗━━━┓
* ┃ ┣┓
* ┃ ┏┛
* ┗┓┓┏━━━━━━━━┳┓┏┛
* ┃┫┫ ┃┫┫
* ┗┻┛ ┗┻┛
*/
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<iostream>
#include<queue>
#include<cmath>
#include<map>
#include<stack>
#include<set>
#define inc(i,l,r) for(int i=l;i<=r;i++)
#define dec(i,l,r) for(int i=l;i>=r;i--)
#define link(x) for(edge *j=h[x];j;j=j->next)
#define mem(a) memset(a,0,sizeof(a))
#define ll long long
#define eps 1e-12
#define succ(x) (1LL<<x)
#define lowbit(x) (x&(-x))
#define sqr(x) ((x)*(x))
#define mid (x+y>>1)
#define NM 100005
#define nm 200010
#define N 1000005
#define M(x,y) x=max(x,y)
const double pi=acos(-1);
const ll inf=1e16+7;
using namespace std;
ll read(){
ll x=0,f=1;char ch=getchar();
while(!isdigit(ch)){if(ch=='-')f=-1;ch=getchar();}
while(isdigit(ch))x=x*10+ch-'0',ch=getchar();
return f*x;
}
struct edge{int t;edge*next;}e[nm],*h[NM],*o=e;
void add(int x,int y){o->t=y;o->next=h[x];h[x]=o++;}
int n,a[NM],b[NM],_t,_x,_y,f[NM],ls[NM],rs[NM],tot;
ll d[NM][2],ans,_ans;
bool v[NM];
int find(int x){return f[x]==x?x:f[x]=find(f[x]);}
void dfs(int x){
v[x]++;d[x][1]=a[x];
link(x)if(j->t!=_x&&f[x]!=j->t){
f[j->t]=x;
dfs(j->t);
d[x][1]+=min(d[j->t][0],d[j->t][1]);
}
ll t=inf;
link(x)if(f[x]!=j->t&&j->t!=_x)t=min(t,d[j->t][1]-min(d[j->t][0],d[j->t][1]));
d[x][0]=min(d[x][1]+t-a[x],d[x][1]-b[x]);
}
int main(){
n=read();
inc(i,1,n)a[i]=read();inc(i,1,n)b[i]=read();
inc(i,1,n)f[i]=i;
inc(i,1,n){
_t=read();
int x=find(_t),y=find(i);
if(x==y){rs[++tot]=_t;ls[tot]=i;continue;}
add(_t,i);f[x]=y;
}
// inc(k,1,tot)printf("::%d %d\n",ls[k],rs[k]);
inc(k,1,tot){
f[ls[k]]=0;_x=0;
dfs(ls[k]);
// inc(i,1,n)printf("%d %d\n",d[i][0],d[i][1]);
ans=min(d[ls[k]][1],d[ls[k]][0]);
add(rs[k],ls[k]);f[rs[k]]=0;_x=rs[k];
dfs(rs[k]);
// inc(i,1,n)printf("%d %d\n",d[i][0],d[i][1]);
ans=min(ans,d[rs[k]][1]);
ans=min(ans,d[rs[k]][0]);
_ans+=ans;
}
return 0*printf("%lld\n",_ans);
}
C 待补
D签到
#include<bits/stdc++.h>
#define inc(i,l,r) for(int i=l;i<=r;i++)
#define dec(i,l,r) for(int i=l;i>=r;i--)
#define mem(a) memset(a,0,sizeof(a))
#define sqr(x) ((x)*(x))
#define ll long long
#define lowbit(x) ((x)&(-x))
#define link(x) for(edge*j=h[x];j;j=j->next)
#define NM 100005
const ll inf=1e18;
ll read(){
ll x=0,f=1;char ch=getchar();
while(!isdigit(ch)){if(ch=='-')f=-1;ch=getchar();}
while(isdigit(ch))x=x*10+ch-'0',ch=getchar();
return x*f;
}
int n;
ll s1,s2,a[NM],d[NM][2],c[NM][2];
int main(){
int _=read();
while(_--){
mem(a);mem(d);mem(c);
n=read();
inc(i,1,n)a[i]=read();
c[0][1]=-inf;
inc(i,1,n){
c[i][0]=c[i-1][0];d[i][0]=d[i-1][0];
if(c[i][0]<c[i-1][1]+a[i]||(c[i][0]==c[i-1][1]+a[i]&&d[i][0]>d[i-1][1])){
c[i][0]=c[i-1][1]+a[i];d[i][0]=d[i-1][1];
}
c[i][1]=c[i-1][1];d[i][1]=d[i-1][1];
if(c[i][1]<c[i-1][0]-a[i]||(c[i][1]==c[i-1][0]-a[i]&&d[i][1]>d[i-1][0]+1)){
c[i][1]=c[i-1][0]-a[i];d[i][1]=d[i-1][0]+1;
}
}
s1=-inf;s2=inf;
inc(i,1,n)inc(j,0,1)if(c[i][j]>s1||(c[i][j]==s1&&d[i][j]<s2)){s1=c[i][j];s2=d[i][j];}
printf("%lld %lld\n",s1,s2*2);
}
return 0;
}
G 二分答案
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll N = 5e5+5;
ll n,T;
ll x[N],a[N],ps_a[N],ps_ax[N];
ll check(ll X)
{
ll now = lower_bound(ps_a+1,ps_a+n+1,X/2)-ps_a;
ll lll = 1,rr = upper_bound(ps_a+1,ps_a+n+1,X)-ps_a,l,r;
if(lll == rr) l = X,r = a[rr]-X;
else l = a[lll],r = a[rr] - (X - ps_a[rr-1]);
ll res = x[now]*ps_a[now-1] - ps_ax[now-1];
if(rr > now)
{
res+=(ps_ax[rr-1]-ps_ax[now])-x[now]*(ps_a[rr-1] - ps_a[now]);
res+=(a[rr]-r)*(x[rr] - x[now]);
}
while(x[rr]-x[now]<=x[now]-x[lll] && lll<now && rr<=n )
{
if(l>r){
res+=(x[rr] - x[now])*r;
res-=(x[now] - x[lll])*r;
l-=r;
rr++;r = a[rr];
}
else if(l<r){
res+=(x[rr]-x[now])*l;
res-=(x[now] - x[lll])*l;
r-=l;
lll++;l = a[lll];
}
else{
res+=(x[rr]-x[now])*l;
res-=(x[now] - x[lll])*l;
lll++;l = a[lll];
rr++;r = a[rr];
}
}
// cout<<X<<"::"<<endl;
// cout<<lll<<"("<<l<<") "<<now<<" "<<rr<<"("<<r<<")"<<res<<endl;
if(res <=T) return 1;
while(now < n)
{
now++;
res += (ps_a[now-1]-ps_a[lll]+l)*(x[now]-x[now-1]);
if(now<=rr)
res -= (ps_a[rr-1]-ps_a[now-1]+(a[rr]-r))*(x[now] - x[now-1]);
while(x[rr]-x[now]<=x[now]-x[lll] && lll<now && rr<=n )
{
if(l>r){
res+=(x[rr] - x[now])*r;
res-=(x[now] - x[lll])*r;
l-=r;
rr++;r = a[rr];
}
else if(l<r){
res+=(x[rr]-x[now])*l;
res-=(x[now] - x[lll])*l;
r-=l;
lll++;l = a[lll];
}
else{
res+=(x[rr]-x[now])*l;
res-=(x[now] - x[lll])*l;
lll++;l = a[lll];
rr++;r = a[rr];
}
}
// cout<<lll<<"("<<l<<") "<<now<<" "<<rr<<"("<<r<<")"<<res<<endl;
if(res<=T) return 1;
}
return 0;
}
int main()
{
ios::sync_with_stdio(false);
cin>>n>>T;
T>>=1;
for(ll i = 1;i<=n;i++)
cin>>x[i];
for(ll i = 1;i<=n;i++)
{
cin>>a[i];
ps_a[i] = ps_a[i-1]+a[i];
ps_ax[i] = ps_ax[i-1]+a[i]*x[i];
}
ll l = 0,r = ps_a[n],ans = 0;
while(l<=r)
{
// cout<<l<<" "<<r<<endl;
ll mid = (l+r)>>1;
if(check(mid)) ans = mid,l = mid+1;
else r = mid-1;
}
cout<<ans<<endl;
}
H
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<iostream>
#include<queue>
#include<cmath>
#include<map>
#include<stack>
#include<set>
#define inc(i,l,r) for(int i=l;i<=r;i++)
#define dec(i,l,r) for(int i=l;i>=r;i--)
#define link(x) for(edge *j=h[x];j;j=j->next)
#define mem(a) memset(a,0,sizeof(a))
#define ll long long
#define eps 1e-12
#define succ(x) (1<<x)
#define lowbit(x) (x&(-x))
#define sqr(x) ((x)*(x))
#define mid (x+y>>1)
#define NM 400005
#define nm 800005
#define N 1000005
#define M(x,y) x=max(x,y)
const double pi=acos(-1);
const ll inf=998244353;
using namespace std;
ll read(){
ll x=0,f=1;char ch=getchar();
while(!isdigit(ch)){if(ch=='-')f=-1;ch=getchar();}
while(isdigit(ch))x=x*10+ch-'0',ch=getchar();
return f*x;
}
struct edge{int t;edge*next;}e[nm],*h[NM],*o=e;
void add(int x,int y){o->t=y;o->next=h[x];h[x]=o++;}
int n,_x,_y,a[NM],f[NM];
ll _g[5],_d[5],_c[5],d[NM][5],c[NM][5],g[NM][5];
void dfs(int x){
d[x][0]=a[x];
c[x][1]=a[x];
link(x)if(j->t!=f[x]){
f[j->t]=x;
dfs(j->t);
mem(_c);mem(_d);mem(_g);
inc(i,0,2)inc(k,1,i)_d[i]=max(_d[i],c[j->t][k]+d[x][i-k]);
inc(i,0,2)inc(k,0,i-1)_d[i]=max(_d[i],d[j->t][k]+a[x]+g[x][i-k]);
inc(i,0,2)_d[i]=max(_d[i],d[j->t][i]+a[x]);
inc(i,1,3)_c[i]=max(_c[i],c[j->t][i]);
inc(i,1,3)_g[i]=max(_g[i],c[j->t][i]);
inc(i,1,3)inc(k,1,i-1)_c[i]=max(_c[i],c[j->t][k]+c[x][i-k]);
inc(i,1,3)inc(k,1,i-1)_g[i]=max(_g[i],c[j->t][k]+g[x][i-k]);
inc(i,1,3)inc(k,0,i-1)_c[i]=max(_c[i],d[j->t][k]+d[x][i-1-k]);
inc(i,1,3)c[x][i]=max(c[x][i],_c[i]);inc(i,0,2)d[x][i]=max(d[x][i],_d[i]);
inc(i,1,3)g[x][i]=max(g[x][i],_g[i]);
}
}
int main(){
n=read();
inc(i,1,n)a[i]=read();
inc(i,1,n-1){_x=read();_y=read();add(_x,_y);add(_y,_x);}
dfs(1);
return 0*printf("%lld\n",c[1][3]);
}
I 签到
#include<bits/stdc++.h>
using namespace std;
int n,m;
int up[100005],down[100005],lleft[100005],ight[100005];
int main()
{
scanf("%d%d",&n,&m);
int x,y;
for(int i = 1;i<=n;i++)
up[i] = down[i] = lleft[i] = ight[i] = 1;
for(int i =1 ;i<=m;i++)
{
scanf("%d%d",&x,&y);
up[y] = down[y] = lleft[x] = ight[x] = 0;
}
int ans = 0;
for(int i = 1;i<=n/2;i++)
{
int c1 = (lleft[i]+ight[n-i+1]+up[n-i+1]+down[i]);
int c2 = (up[i]+ight[i]+lleft[n-i+1]+down[n-i+1]);
ans+=max(c1,c2);
}
if(n%2) ans+=(up[n/2+1]|down[n/2+1]|lleft[n/2+1]|ight[n/2+1]);
printf("%d\n",ans);
}
J
考虑分治贡献 对于每个位置除了被本身的值贡献以外 看是否还有其他的值作用于这个点 来判断这个点是否对答案产生贡献
#include <bits/stdc++.h>
const int MAXN=2e6+10;
#define ll long long
using namespace std;
typedef struct node{
int x,y,vul;int flag;
friend bool operator<(node aa,node bb){
if(aa.x==bb.x&&aa.y==bb.y)return aa.flag>bb.flag;
else if(aa.x==bb.x) return aa.y>bb.y;
return aa.x>bb.x;
}
}node;
node d[MAXN*5],d1[MAXN*5];
ll read(){
ll x=0,f=1;char ch=getchar();
while(!isdigit(ch)){if(ch=='-')f=-1;ch=getchar();}
while(isdigit(ch))x=x*10+ch-'0',ch=getchar();
return x*f;
}
int n,m,q,sz;
int ans[MAXN];int p,num[MAXN];
int cnt1=0;
void cdq(int l,int mid,int r){
int i=l;int j=mid+1;cnt1=0;p=0;
while(i<=mid&&j<=r){
while(i<=mid&&d[i].y>=d[j].y){
d1[++cnt1]=d[i];
if(d[i].flag==2){p--;num[d[i].vul]--;}
if(d[i].flag==1){p++;num[d[i].vul]++;}
i++;
}
if(!d[j].flag)ans[(d[j].x-1)*m+d[j].y]+=p-num[d[j].vul];
d1[++cnt1]=d[j];j++;
}
if(i<=mid){
for(;i<=mid;i++)d1[++cnt1]=d[i];
}
if(j<=r){
for(;j<=r;j++){
if(!d[j].flag)ans[(d[j].x-1)*m+d[j].y]+=p-num[d[j].vul];
d1[++cnt1]=d[j];
}
}
for(int i=1;i<=cnt1;i++)d[l+i-1]=d1[i],num[d1[i].vul]=0;
}
void guibin(int l,int r){
if(l>=r)return ;
int mid=(l+r)>>1;
guibin(l,mid);
guibin(mid+1,r);
cdq(l,mid,r);
}
int main(){
n=read();m=read();q=read();
int cnt=0;sz=(n)*(m);
for(int i=1;i<=n;i++){
for(int j=1;j<=m;j++){
d[++cnt].x=i;d[cnt].y=j;d[cnt].vul=read();d[cnt].flag=0;
}
}
int x1,y1,x2,y2,vul;
for(int i=1;i<=q;i++){
x1=read();y1=read();x2=read();y2=read();vul=read();
d[++cnt].x=x2;d[cnt].y=y2;d[cnt].vul=vul;d[cnt].flag=1;
d[++cnt].x=x1-1;d[cnt].y=y2;d[cnt].vul=vul;d[cnt].flag=2;
d[++cnt].x=x2;d[cnt].y=y1-1;d[cnt].vul=vul;d[cnt].flag=2;
d[++cnt].x=x1-1;d[cnt].y=y1-1;d[cnt].vul=vul;d[cnt].flag=1;
}
sort(d+1,d+cnt+1);
// cout<<"====="<<endl;
// for(int i=1;i<=cnt;i++)cout<<d[i].x<<" "<<d[i].y<<" "<<d[i].flag<<endl;
// cout<<"====="<<endl;
guibin(1,cnt);
// for(int i=1;i<=sz;i++)cout<<ans[i]<<" ";
// cout<<endl;
int ans1=0;
for(int i=1;i<=n;i++){
for(int j=1;j<=m;j++){
if(ans[(i-1)*m+j]>=1)ans1++;
}
}
printf("%d\n",ans1);
return 0;
}
