Mex
Time Limit: 15000/5000 MS (Java/Others) Memory Limit: 65535/65535 K (Java/Others)
Total Submission(s): 1414 Accepted Submission(s): 464
Total Submission(s): 1414 Accepted Submission(s): 464
Problem Description
Mex is a function on a set of integers, which is universally used for impartial game theorem. For a non-negative integer set S, mex(S) is defined as the least non-negative integer which is not appeared in S. Now our problem is about mex function on a sequence.
Consider a sequence of non-negative integers {ai}, we define mex(L,R) as the least non-negative integer which is not appeared in the continuous subsequence from aL to aR, inclusive. Now we want to calculate the sum of mex(L,R) for all 1 <= L <= R <= n.
Consider a sequence of non-negative integers {ai}, we define mex(L,R) as the least non-negative integer which is not appeared in the continuous subsequence from aL to aR, inclusive. Now we want to calculate the sum of mex(L,R) for all 1 <= L <= R <= n.
Input
The input contains at most 20 test cases.
For each test case, the first line contains one integer n, denoting the length of sequence.
The next line contains n non-integers separated by space, denoting the sequence.
(1 <= n <= 200000, 0 <= ai <= 10^9)
The input ends with n = 0.
For each test case, the first line contains one integer n, denoting the length of sequence.
The next line contains n non-integers separated by space, denoting the sequence.
(1 <= n <= 200000, 0 <= ai <= 10^9)
The input ends with n = 0.
Output
For each test case, output one line containing a integer denoting the answer.
Sample Input
3 0 1 3 5 1 0 2 0 1 0
Sample Output
5 24HintFor the first test case: mex(1,1)=1, mex(1,2)=2, mex(1,3)=2, mex(2,2)=0, mex(2,3)=0,mex(3,3)=0. 1 + 2 + 2 + 0 +0 +0 = 5.
Source
Recommend
liuyiding
这题真是做了很长时间啊,但是还是没有过,代码已经出来了,自几测试了上百组数据都过了,交上去就是wa,求数据啊,求数据,求数据,急切的求数据。
终于发现错误了,其实三四天前的代码,只要改一下输出就对了,用long long ,要用cout,否则会错,三四天前的代码如果改成cout<<ans<<endl; 就过了,只不过那时候我怀疑用map映射的时候,映射10^9 ,会出错,就没有向输出考虑,于是就把代码改了,改的时候忽略了一个问题,我把大于200000的没有加到数组中,当时只是以为大于200000的没用,其实还是很有用的,我没仔细想想,就以为他一点用没有,导致这三四天来,反复的改代码都wa。哎,慎重,一定要慎重啊!
三四天前改后AC的代码:
这题真是做了很长时间啊,但是还是没有过,代码已经出来了,自几测试了上百组数据都过了,交上去就是wa,求数据啊,求数据,求数据,急切的求数据。
终于发现错误了,其实三四天前的代码,只要改一下输出就对了,用long long ,要用cout,否则会错,三四天前的代码如果改成cout<<ans<<endl; 就过了,只不过那时候我怀疑用map映射的时候,映射10^9 ,会出错,就没有向输出考虑,于是就把代码改了,改的时候忽略了一个问题,我把大于200000的没有加到数组中,当时只是以为大于200000的没用,其实还是很有用的,我没仔细想想,就以为他一点用没有,导致这三四天来,反复的改代码都wa。哎,慎重,一定要慎重啊!
#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
#define N 200010
#define INF 0x7ffffff
using namespace std;
struct num
{
int l,r;
__int64 col,Max,sum;
}a[4*N];
int pt[N],b[N],tag[N],pos1,pos2;
int q[N];
int main()
{
//freopen("data.in","r",stdin);
//freopen("data1.out","w",stdout);
void build(int k,int l,int r);
void del(int k,int val);
void find(int k,int val);
void update(int k,int l,int r,int val);
int n;
while(scanf("%d",&n)!=EOF)
{
if(n==0)
{
break;
}
int Top=1;
for(int i=1;i<=n;i++)
{
scanf("%d",&b[Top]);
if(b[Top]<=200000) //错误之处
{
Top++;
}
}
n = Top-1;
if(n==0)
{
printf("0\n");
continue;
}
memset(q,0,sizeof(q));
int res = 0;
__int64 ans=0;
for(int i=1;i<=n;i++)
{
q[b[i]]=1;
while(q[res]!=0)
{
res++;
}
tag[i] = res;
ans+=(__int64)res;
}
memset(pt,0,sizeof(pt));
memset(q,0,sizeof(q));
for(int i=1;i<=n;i++)
{
int x=b[i];
if(q[x]!=0)
{
pt[q[x]]=i;
}
q[x]=i;
}
build(1,1,n);
for(int i=1;i<=n;i++)
{
del(1,i);
pos1 = INF;
int val=b[i];
if(a[1].Max<val)
{
ans+=a[1].sum;
continue;
}
find(1,val);
pos2 = pt[i]-1;
if(pos2 ==-1)
{
pos2 = n;
}
if(pos1>pos2)
{
ans+=a[1].sum;
continue;
}
update(1,pos1,pos2,val);
ans+=a[1].sum;
}
cout<<ans<<endl;
}
return 0;
}
void pushup(int k)
{
a[k].Max = max(a[k<<1].Max,a[k<<1|1].Max);
a[k].sum = a[k<<1].sum+a[k<<1|1].sum;
a[k].col= 1;
}
void build(int k,int l,int r)
{
a[k].l = l;
a[k].r = r;
if(l==r)
{
a[k].sum = tag[l];
a[k].Max = tag[l];
a[k].col = 0;
return;
}
int mid = (l+r)>>1;
build(k<<1,l,mid);
build(k<<1|1,mid+1,r);
pushup(k);
}
void del(int k,int val)
{
if(a[k].l==a[k].r)
{
a[k].col=0;
a[k].sum=0;
return ;
}
if(a[k].col==0)
{
a[k<<1].col=0;
a[k<<1].Max = a[k].Max;
a[k<<1].sum = a[k].Max*(__int64)(a[k<<1].r-a[k<<1].l+1);
a[k<<1|1].col=0;
a[k<<1|1].Max = a[k].Max;
a[k<<1|1].sum = a[k].Max*(__int64)(a[k<<1|1].r-a[k<<1|1].l+1);
}
int mid = (a[k].l+a[k].r)>>1;
if(mid>=val)
{
del(k<<1,val);
}else
{
del(k<<1|1,val);
}
pushup(k);
}
void find(int k,int val)
{
if(a[k].col==0&&a[k].Max>val)
{
pos1 = a[k].l;
return ;
}
if(a[k].col==0)
{
return;
}
if(a[k].l==a[k].r&&a[k].Max>val)
{
pos1 = a[k].l;
return ;
}
if(a[k<<1].Max>val)
{
find(k<<1,val);
}else if(a[k<<1|1].Max>val)
{
find(k<<1|1,val);
}
}
void update(int k,int l,int r,int val)
{
if(a[k].l==l&&a[k].r==r)
{
a[k].Max = val;
a[k].sum = (__int64)(a[k].r -a[k].l + 1)*(__int64)val;
a[k].col=0;
return ;
}
if(a[k].col==0)
{
a[k<<1].col=0;
a[k<<1].Max = a[k].Max;
a[k<<1].sum = a[k].Max*(__int64)(a[k<<1].r-a[k<<1].l+1);
a[k<<1|1].col=0;
a[k<<1|1].Max = a[k].Max;
a[k<<1|1].sum = a[k].Max*(__int64)(a[k<<1|1].r-a[k<<1|1].l+1);
}
int mid = (a[k].l+a[k].r)>>1;
if(r<=mid)
{
update(k<<1,l,r,val);
}else if(l>mid)
{
update(k<<1|1,l,r,val);
}else
{
update(k<<1,l,mid,val);
update(k<<1|1,mid+1,r,val);
}
pushup(k);
}
AC的代码:
#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
#define N 200010
#define INF 0x7ffffff
using namespace std;
struct num
{
int l,r;
__int64 col,Max,sum;
}a[4*N];
int pt[N],b[N],tag[N],pos1,pos2;
int q[N];
int main()
{
//freopen("data.in","r",stdin);
//freopen("data1.out","w",stdout);
void build(int k,int l,int r);
void del(int k,int val);
void find(int k,int val);
void update(int k,int l,int r,int val);
int n;
while(scanf("%d",&n)!=EOF)
{
if(n==0)
{
break;
}
for(int i=1;i<=n;i++)
{
scanf("%d",&b[i]);
}
memset(q,0,sizeof(q));
int res = 0;
__int64 ans=0;
for(int i=1;i<=n;i++)
{
if(b[i]<=200000)
{
q[b[i]]=1;
}
while(q[res]!=0)
{
res++;
}
tag[i] = res;
ans+=(__int64)res;
}
memset(pt,0,sizeof(pt));
memset(q,0,sizeof(q));
for(int i=1;i<=n;i++)
{
int x=b[i];
if(x>200000)
{
continue;
}
if(q[x]!=0)
{
pt[q[x]]=i;
}
q[x]=i;
}
build(1,1,n);
for(int i=1;i<=n;i++)
{
del(1,i);
pos1 = INF;
int val=b[i];
if(a[1].Max<val)
{
ans+=a[1].sum;
continue;
}
find(1,val);
pos2 = pt[i]-1;
if(pos2 ==-1)
{
pos2 = n;
}
if(pos1>pos2)
{
ans+=a[1].sum;
continue;
}
update(1,pos1,pos2,val);
ans+=a[1].sum;
}
cout<<ans<<endl;
}
return 0;
}
void pushup(int k)
{
a[k].Max = max(a[k<<1].Max,a[k<<1|1].Max);
a[k].sum = a[k<<1].sum+a[k<<1|1].sum;
a[k].col= 1;
}
void build(int k,int l,int r)
{
a[k].l = l;
a[k].r = r;
if(l==r)
{
a[k].sum = tag[l];
a[k].Max = tag[l];
a[k].col = 0;
return;
}
int mid = (l+r)>>1;
build(k<<1,l,mid);
build(k<<1|1,mid+1,r);
pushup(k);
}
void del(int k,int val)
{
if(a[k].l==a[k].r)
{
a[k].col=0;
a[k].sum=0;
return ;
}
if(a[k].col==0)
{
a[k<<1].col=0;
a[k<<1].Max = a[k].Max;
a[k<<1].sum = a[k].Max*(__int64)(a[k<<1].r-a[k<<1].l+1);
a[k<<1|1].col=0;
a[k<<1|1].Max = a[k].Max;
a[k<<1|1].sum = a[k].Max*(__int64)(a[k<<1|1].r-a[k<<1|1].l+1);
}
int mid = (a[k].l+a[k].r)>>1;
if(mid>=val)
{
del(k<<1,val);
}else
{
del(k<<1|1,val);
}
pushup(k);
}
void find(int k,int val)
{
if(a[k].col==0&&a[k].Max>val)
{
pos1 = a[k].l;
return ;
}
if(a[k].col==0)
{
return;
}
if(a[k].l==a[k].r&&a[k].Max>val)
{
pos1 = a[k].l;
return ;
}
if(a[k<<1].Max>val)
{
find(k<<1,val);
}else if(a[k<<1|1].Max>val)
{
find(k<<1|1,val);
}
}
void update(int k,int l,int r,int val)
{
if(a[k].l==l&&a[k].r==r)
{
a[k].Max = val;
a[k].sum = (__int64)(a[k].r -a[k].l + 1)*(__int64)val;
a[k].col=0;
return ;
}
if(a[k].col==0)
{
a[k<<1].col=0;
a[k<<1].Max = a[k].Max;
a[k<<1].sum = a[k].Max*(__int64)(a[k<<1].r-a[k<<1].l+1);
a[k<<1|1].col=0;
a[k<<1|1].Max = a[k].Max;
a[k<<1|1].sum = a[k].Max*(__int64)(a[k<<1|1].r-a[k<<1|1].l+1);
}
int mid = (a[k].l+a[k].r)>>1;
if(r<=mid)
{
update(k<<1,l,r,val);
}else if(l>mid)
{
update(k<<1|1,l,r,val);
}else
{
update(k<<1,l,mid,val);
update(k<<1|1,mid+1,r,val);
}
pushup(k);
}
三四天前改后AC的代码:
#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <map>
#define N 200010
using namespace std;
struct num
{
long long int l,r,color,Max,sum;
}a[5*N];
map<int,int>q;
int pt[N],b[N],tag[N],pos1,pos2;
int main()
{
//freopen("data.in","r",stdin);
void build(int k,int l,int r);
void del(int k,int val);
void find(int k,int val);
void update(int k,int l,int r,int val);
int n;
while(scanf("%d",&n)!=EOF)
{
if(n==0)
{
break;
}
for(int i=1;i<=n;i++)
{
scanf("%d",&b[i]);
}
q.clear();
int res = 0;
long long int ans=0;
for(int i=1;i<=n;i++)
{
q[b[i]]=1;
while(q[res]!=0)
{
res++;
}
tag[i] = res;
ans+=(long long int)res;
}
q.clear();
memset(pt,0,sizeof(pt));
for(int i=1;i<=n;i++)
{
int x=b[i];
if(q[x]!=0)
{
pt[q[x]]=i;
}
q[x]=i;
}
build(1,1,n);
for(int i=1;i<=n;i++)
{
del(1,i);
int val=b[i];
find(1,val);
pos2 = pt[i]-1;
if(pos2 ==-1)
{
pos2 = n;
}
if(pos1>pos2||a[1].Max<val)
{
ans+=a[1].sum;
continue;
}
update(1,pos1,pos2,val);
ans+=a[1].sum;
}
cout<<ans<<endl;
}
return 0;
}
void pushup(int k)
{
a[k].Max = max(a[k<<1].Max,a[k<<1|1].Max);
a[k].sum = a[k<<1].sum+a[k<<1|1].sum;
a[k].color = 1;
}
void build(int k,int l,int r)
{
a[k].l = l;
a[k].r = r;
if(l==r)
{
a[k].sum = tag[l];
a[k].Max = tag[l];
a[k].color = 0;
return;
}
int mid = (l+r)>>1;
build(k<<1,l,mid);
build(k<<1|1,mid+1,r);
pushup(k);
}
void del(int k,int val)
{
if(a[k].l==a[k].r)
{
a[k].color=0;
a[k].sum=0;
return ;
}
if(a[k].color==0)
{
a[k<<1].color=0;
a[k<<1].Max = a[k].Max;
a[k<<1].sum = a[k].Max*(long long int)(a[k<<1].r-a[k<<1].l+1);
a[k<<1|1].color=0;
a[k<<1|1].Max = a[k].Max;
a[k<<1|1].sum = a[k].Max*(long long int)(a[k<<1|1].r-a[k<<1|1].l+1);
}
int mid = (a[k].l+a[k].r)>>1;
if(mid>=val)
{
del(k<<1,val);
}else
{
del(k<<1|1,val);
}
pushup(k);
}
void find(int k,int val)
{
if(a[k].color==0&&a[k].Max>val)
{
pos1 = a[k].l;
return ;
}
if(a[k].color==0)
{
return;
}
if(a[k].l==a[k].r&&a[k].Max>val)
{
pos1 = a[k].l;
return ;
}
if(a[k<<1].Max>val)
{
find(k<<1,val);
}else if(a[k<<1|1].Max>val)
{
find(k<<1|1,val);
}
}
void update(int k,int l,int r,int val)
{
if(a[k].l==l&&a[k].r==r)
{
a[k].Max = val;
a[k].sum = (a[k].r -a[k].l + 1)*val;
a[k].color=0;
return ;
}
if(a[k].color==0)
{
a[k<<1].color=0;
a[k<<1].Max = a[k].Max;
a[k<<1].sum = a[k].Max*(a[k<<1].r-a[k<<1].l+1);
a[k<<1|1].color=0;
a[k<<1|1].Max = a[k].Max;
a[k<<1|1].sum = a[k].Max*(a[k<<1|1].r-a[k<<1|1].l+1);
}
int mid = (a[k].l+a[k].r)>>1;
if(r<=mid)
{
update(k<<1,l,r,val);
}else if(l>mid)
{
update(k<<1|1,l,r,val);
}else
{
update(k<<1,l,mid,val);
update(k<<1|1,mid+1,r,val);
}
pushup(k);
}