Codeforces_825

A.连续1的个数，0用来分割，注意连续的0。

#include<bits/stdc++.h>
using namespace std;

int n;
string s;

int main()
{
    ios::sync_with_stdio(0);
    cin >> n >> s;
    int now = 0,flag = 0;
    for(int i = 0;i < n;i++)
    {
        if(s[i] == '1') now++,flag = 0;
        else
        {
            cout << now;
            now = 0;
            flag = 1;
        }
    }
    if(now || flag) cout << now;
    cout << endl;
    return 0;
}

---

B.暴力每个点放X，判断即可。

#include<bits/stdc++.h>
using namespace std;

string s[15];

bool ok()
{
    for(int i = 1;i <= 10;i++)
    {
        for(int j = 1;j <= 10;j++)
        {
            if(i <= 6)
            {
                int flag = 1;
                for(int ii = i;ii < i+5;ii++)
                {
                    if(s[ii][j] != 'X') flag = 0;
                }
                if(flag)    return 1;
            }
            if(j <= 6)
            {
                int flag = 1;
                for(int jj = j;jj < j+5;jj++)
                {
                    if(s[i][jj] != 'X') flag = 0;
                }
                if(flag)    return 1;
            }
            if(i <= 6 && j <= 6)
            {
                int flag = 1;
                for(int ii = i,jj = j;ii < i+5;ii++,jj++)
                {
                    if(s[ii][jj] != 'X')    flag = 0;
                }
                if(flag)    return 1;
            }
            if(i >= 5 && j <= 6)
            {
                int flag = 1;
                for(int ii = i,jj = j;ii > i-5;ii--,jj++)
                {
                    if(s[ii][jj] != 'X')   flag = 0;
                }
                if(flag)    return 1;
            }
        }
    }
    return 0;
}
int main()
{
    ios::sync_with_stdio(0);
    for(int i = 1;i <= 10;i++)
    {
        cin >> s[i];
        s[i] = ' '+s[i];
    }
    for(int i = 1;i <= 10;i++)
    {
        for(int j = 1;j <= 10;j++)
        {
            if(s[i][j] != '.') continue;
            s[i][j] = 'X';
            if(ok())
            {
                cout << "YES" << endl;
                return 0;
            }
            s[i][j] = '.';
        }
    }
    cout << "NO" << endl;
    return 0;
}

---

C.排序后模拟。

#include<bits/stdc++.h>
using namespace std;

int n,k,a[1005];

int main()
{
    ios::sync_with_stdio(0);
    cin >> n >> k;
    for(int i = 1;i <= n;i++)   cin >> a[i];
    sort(a+1,a+1+n);
    int ans = 0;
    for(int i = 1;i <= n;i++)
    {
        while(k*2 < a[i])
        {
            k *= 2;
            ans++;
        }
        k = max(k,a[i]);
    }
    cout << ans << endl;
    return 0;
}

---

D.模拟，给字母少的先分配。

#include<bits/stdc++.h>
using namespace std;

string s1,s2;
map<char,int> mp;

int main()
{
    ios::sync_with_stdio(0);
    cin >> s1 >> s2;
    for(int i = 0;i < s1.length();i++)  mp[s1[i]]++;
    int now = 0;
    for(int i = 0;i < s1.length();i++)
    {
        if(s1[i] != '?')    continue;
        now = (now+1)%s2.length();
        if(mp[s2[now]])
        {
            mp[s2[now]]--;
            i--;
        }
        else    s1[i] = s2[now];
    }
    cout << s1 << endl;
    return 0;
}

---

E.优先队列逆向拓扑排序。

#include<bits/stdc++.h>
using namespace std;

int n,m,in[200005] = {0},ans[200005];
vector<int> v[200005];

int main()
{
    ios::sync_with_stdio(0);
    cin >> n >> m;
    while(m--)
    {
        int x,y;
        cin >> x >> y;
        v[y].push_back(x);
        in[x]++;
    }
    priority_queue<int> q;
    for(int i = 1;i <= n;i++)
    {
        if(!in[i])  q.push(i);
    }
    int cnt = n;
    while(!q.empty())
    {
        int now = q.top();
        q.pop();
        ans[now] = cnt--;
        for(int i = 0;i < v[now].size();i++)
        {
            int t = v[now][i];
            if(--in[t] == 0)    q.push(t);
        }
    }
    for(int i = 1;i <= n;i++)   cout << ans[i] << " ";
    cout << endl;
    return 0;
}

---

F.预处理最长公共前缀，dp枚举最小串。

#include<bits/stdc++.h>
using namespace std;

string s;
int lcp[8005][8005] = {0},dp[8005],cnt[8005];

int main()
{
    ios::sync_with_stdio(0);
    cin >> s;
    int n = s.length();
    memset(dp,0x3f,sizeof(dp));
    for(int i = 1;i <= 9;i++)   cnt[i] = 1;
    for(int i = 10;i <= 99;i++) cnt[i] = 2;
    for(int i = 100;i <= 999;i++)   cnt[i] = 3;
    for(int i = 1000;i <= 8000;i++) cnt[i] = 4;
    for(int i = n-1;i >= 0;i--)
    {
        for(int j = n-1;j >= i;j--)
        {
            if(s[i] == s[j])    lcp[i][j] = lcp[i+1][j+1]+1;
            else    lcp[i][j] = 0;
        }
    }
    dp[0] = 0;
    for(int i = 0;i < n;i++)
    {
        for(int j = 1;i+j <= n;j++)
        {
            for(int k = i+j,t = 1;k <= n;k += j,t++)
            {
                if(lcp[i][k-j] < j)  break;
                dp[k] = min(dp[k],dp[i]+j+cnt[t]);
            }
        }
    }
    cout << dp[n] << endl;
    return 0;
}

---

G.记录一个最小的点即可。

#include<bits/stdc++.h>
using namespace std;

int n,q,ans[1000005];
vector<int> v[1000005];

int dfs(int now,int pre)
{
    for(int i = 0;i < v[now].size();i++)
    {
        int t = v[now][i];
        if(t == pre)    continue;
        ans[t] = min(t,ans[now]);
        dfs(t,now);
    }
}

int main()
{
    ios::sync_with_stdio(0);
    cin >> n >> q;
    int x,y;
    for(int i = 1;i < n;i++)
    {
        cin >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    int lastt = 0;
    cin >> x >> y;
    y = (lastt+y)%n+1;
    ans[y] = y;
    dfs(y,-1);
    int minn = y;
    while(--q)
    {
        int x,y;
        cin >> x >> y;
        y = (y+lastt)%n+1;
        if(x == 1)  minn = min(minn,ans[y]);
        else
        {
            lastt = min(ans[y],minn);
            cout << lastt << endl;
        }
    }
    return 0;
}