Codeforces Round #442 (Div. 2)

A.

#include<bits/stdc++.h>using namespace std;typedef long long ll;int main(){    string s;    cin >> s;    vector < string > v;    v.push_back ("Danil");    v.push_back ("Olya");    v.push_back ("Slava");    v.push_back ("Ann");    v.push_back ("Nikita");    int ans = 0;    for (int i = 0; i < s.size(); ++ i)    {        for (int j = 0; j < v.size(); ++ j)        {            string S = v[j];            if (s.substr(i, S.size()) == S)                ans++ ;        }    }    if (ans == 1)        cout << "YES";    else        cout << "NO";    return 0;}

B.

#include<bits/stdc++.h>using namespace std;typedef long long ll;const int MAXN=5005,INF=5005;int cnt[MAXN][2];char s[MAXN];int main(){scanf("%s",s+1);int n=strlen(s+1),ans=INF;for(int i=1;i<=n;i++)    {cnt[i][s[i]-'a']=1;for(int j=0;j<2;j++)cnt[i][j]+=cnt[i-1][j];}for(int i=0;i<=n;i++)for(int j=i;j<=n;j++)ans=min(ans,cnt[i][1]+cnt[j][0]-cnt[i][0]+cnt[n][1]-cnt[j][1]);printf("%d\n",n-ans);return 0;}

C.

#include<bits/stdc++.h>using namespace std;typedef long long ll;int main(){    int n;    scanf("%d",&n);    printf("%d\n",n+n/2);    for(int i=2;i<=n;i+=2)printf("%d ",i);for(int i=1;i<=n;i+=2)printf("%d ",i);    for(int i=2;i<=n;i+=2)printf("%d ",i);return 0;}

D.

#include<bits/stdc++.h>using namespace std;char G[1009][1009];int dis[1005][1005];int xx1, yy1, xx2, yy2;int n, m, k;const int dx[4] = { 0,0,-1,1 };const int dy[4] = { 1,-1,0,0 };int bfs(){memset(dis, -1, sizeof(dis));dis[xx1][yy1] = 0;if (xx1 == xx2&&yy1 == yy2)return 0;queue<int>q;q.push(xx1*m + yy1);while (q.size())    {int t = q.front(); q.pop();int x = t / m, y = t%m;for (int i = 0; i < 4; i++){for (int j = 1; j <= k; j++){int nx = x + j*dx[i];int ny = y + j*dy[i];if (G[nx][ny] == '#' || nx < 0 || nx >= n || ny < 0 || ny >= m)                    break;if (dis[nx][ny] < 0){dis[nx][ny] = dis[x][y] + 1;if (nx == xx2&&ny == yy2)                        return dis[nx][ny];q.push(nx*m + ny);}}}}return -1;}int main(){scanf("%d%d%d", &n, &m, &k);for (int i = 0; i < n; i++)scanf("%s", G[i]);scanf("%d%d%d%d", &xx1, &yy1, &xx2, &yy2);xx1--, xx2--, yy1--, yy2--;printf("%d", bfs());}

E.

#include <iostream>#include <cstring>#include <cstdio>#include <vector>#define lson (i << 1)#define rson ((i << 1) | 1)using namespace std;const int M = 2e5 + 10;int a[M], pos[M], leng[M], pre[M], cnt;vector<int> vc[M];struct TnT{int l, r, sum, lazy;}T[M << 2];void push_up(int i){T[i].sum = T[lson].sum + T[rson].sum;}void push_down(int i){if (T[i].lazy){T[lson].sum = T[lson].r - T[lson].l + 1 - T[lson].sum;T[rson].sum = T[rson].r - T[rson].l + 1 - T[rson].sum;T[lson].lazy ^= 1;T[rson].lazy ^= 1;T[i].lazy = 0;}}void build(int l, int r, int i){int mid = (l + r) >> 1;T[i].l = l, T[i].r = r, T[i].sum = 0, T[i].lazy = 0;if (l == r){T[i].sum = a[pre[l]];return;}push_down(i);build(l, mid, lson);build(mid + 1, r, rson);push_up(i);}void update(int l, int r, int i){int mid = (T[i].l + T[i].r) >> 1;if (T[i].l == l && T[i].r == r){T[i].sum = (T[i].r - T[i].l + 1) - T[i].sum;//就是总个数减去以前是亮着的个数就是现在没有亮的个数T[i].lazy ^= 1;return;}push_down(i);if (mid < l){update(l, r, rson);}else if (mid >= r){update(l, r, lson);}else{update(l, mid, lson), update(mid + 1, r, rson);}push_up(i);}int query(int l, int r, int i){int mid = (T[i].l + T[i].r) >> 1;if (T[i].l == l && T[i].r == r){return T[i].sum;}push_down(i);if (mid < l){return query(l, r, rson);}else if (mid >= r){return query(l, r, lson);}else{return query(l, mid, lson) + query(mid + 1, r, rson);}}void dfs(int u){int len = vc[u].size();for (int i = 0; i < len; i++){int v = vc[u][i];pos[v] = ++cnt;pre[cnt] = v;dfs(v);leng[v] = cnt;}}int main(){int n, x, q;char s[123];scanf("%d", &n);for (int i = 2; i <= n; i++){scanf("%d", &x);vc[x].push_back(i);}for (int i = 1; i <= n; i++){scanf("%d", &a[i]);}scanf("%d", &q);cnt = 0;pos[1] = ++cnt;pre[cnt] = 1;leng[1] = n;dfs(1);build(1, n, 1);while (q--){scanf("%s", s);if (s[0] == 'g'){scanf("%d", &x);printf("%d\n", query(pos[x], leng[x], 1));}else{scanf("%d", &x);update(pos[x], leng[x], 1);}}return 0;}