Replace A

You are given a string SS containing only letters A or B. You can take any two adjacent As and replace them by a single A. You perform operations as long as possible. Print the final string.

Standard input

The first line contains the string SS.

Standard output

Print the final string on the first line.

Constraints and notes

• SS contains between 11 and 100100 characters.

AAABB

ABB

和上次CF的A一樣，直接暴力

#include<bits/stdc++.h>
using namespace std;
const int N=2005;
int main()
{
    ios::sync_with_stdio(false);
    string s,t;
    cin>>s;
    set<char>S;
    S.insert(‘A‘);
    while(true)
    {
        int f=1;
        
 
for(int i=1;s[i]&&f;i++)
        {
            if(S.count(s[i-1])&&S.count(s[i]))
            {
                f=0;
                t=s.substr(0,i)+s.substr(i+1);
            }
        }
        if(f)break;
        s=t;
    }
    cout<<s;
    return 0;
}

Matrix Balls

You are given a matrix AA of size N \times MN×M, containing distinct elements. Initially there is a ball placed in every cell of the matrix. Each ball follows the following movement:

• If the current cell is smaller than all of its (at most 88) neighbours, the ball stops in this cell;
• otherwise, the ball moves to the smallest neighbouring cell.

Find for each cell of AA how many balls will end up there, when all the balls stop moving.

Standard input

The first line contains two integers NN and MM.

Each of the next NN lines contains MM integers representing the elements of AA.

Standard output

Print NN lines, each containing MM integers. The j^{th}j?th?? element on the i^{th}i?th?? line should represent the number of balls that end up in cell (i, j)(i,j).

Constraints and notes

• 1 \leq N, M \leq 5001≤N,M≤500
• 0 \leq A_{i, j} \leq 3*10^50≤A?i,j??≤3?10?5??

3 3
1 3 4
5 6 7
8 9 2

6 0 0 
0 0 0 
0 0 3 

1 6
10 20 3 4 5 6

1 0 5 0 0 0 

4 4
20 2 13 1
4 11 10 35
3 12 9 7
30 40 50 5

0 4 0 4 
0 0 0 0 
4 0 0 0 
0 0 0 4 

一個球可以向八個方向滾，滾到最小的裏面，問最後每個那裏面放幾個

必須要記憶化搜索，但是要多搜幾個方向的

#include<bits/stdc++.h>
using namespace std;
const int N=505;
int a[N][N],b[N][N],n,m;
int d[8][2]= {1,0,1,1,1,-1,0,1,0,-1,-1,0,-1,1,-1,-1};
int main()
{
    ios::sync_with_stdio(false);
    cin>>n>>m;
    for(int i=0; i<n; i++)
        for(int j=0; j<m; j++)
            cin>>a[i][j],b[i][j]=1;
    int f=1;
    while(f)
    {
        f=0;
        for(int i=0; i<n; i++)
            for(int j=0; j<m; j++)
                if(b[i][j])
                {
                    int x=i,y=j;
                    for(int k=0; k<8; k++)
                    {
                        int tx=i+d[k][0],ty=j+d[k][1];
                        if(!(tx<0||tx>=n||ty<0||ty>=m)&&a[tx][ty]<a[x][y])
                        x=tx,y=ty;
                    }
                    if(x!=i||y!=j)
                        b[x][y]+=b[i][j],b[i][j]=0,f=1;
                }
    }
    for(int i=0; i<n; i++)
    {
        for(int j=0; j<m; j++)
            cout<<b[i][j]<<" ";
        cout<<"\n";
    }
    return 0;
}

按照數不同往下搜索

#include<bits/stdc++.h>
using namespace std;
const int N=3e5+5;
int d[8][2]= {1,0,1,1,1,-1,0,1,0,-1,-1,0,-1,1,-1,-1};
int n,m,a[505][505],b[505][505];
pair<int,int>g[N];
int main()
{
    cin>>n>>m;
    for(int i=1; i<=n; i++)
        for(int j=1; j<=m; j++)
            b[i][j]=1,cin>>a[i][j],g[a[i][j]]=make_pair(i,j);
    for(int i=300000; i>=0; --i)
    {
        if(g[i].first==0)continue;
        int x=g[i].first,y=g[i].second,mi=i,sx=0,sy=0;
        for(int j=0; j<8; j++)
        {
            int tx=x+d[j][0],ty=y+d[j][1];
            if(tx<1||ty<1||tx>n||ty>m)continue;
            if(a[tx][ty]<mi)
                mi=a[tx][ty],sx=tx,sy=ty;
        }
        if(mi!=i)b[sx][sy]+=b[x][y],b[x][y]=0;
    }
    for(int i=1; i<=n; i++)
    {
        for(int j=1; j<=m; j++)
            cout<<b[i][j]<<" ";
        cout<<"\n";
    }
    return 0;
}

Binary Differences

You are given a binary array AA of size NN. We define the cost of a subarray to be the number of 00s minus the number of 11s in the subarray. Find the number of distinct values KK such that there is at least one subarray of cost KK.

Standard input

The first line contains one integer NN.

The second line contains NN integers (00 or 11) representing the elements of AA.

Standard output

Print the answer on the first line.

Constraints and notes

• 1 \leq N \leq 10^51≤N≤10?5??
• The subarray may be empty

3
0 1 0

3

4
1 0 0 1

4

這個是模擬

#include<bits/stdc++.h>
using namespace std;
int n,mi,ma,x,s,mis,mas;
int main()
{
    cin>>n;
    for(int i=1; i<=n; ++i)
    {
        cin>>x;
        if(!x)s++;
        else s--;
        mi=min(mi,s-mas),ma=max(ma,s-mis),mas=max(mas,s),mis=min(mis,s);
    }
    cout<<ma-mi+1;
    return 0;
}

Round #71 (Div. 2 only)