Codeforces Round #772 (Div. 2)

A

#include <bits/stdc++.h>
#define LL long long
using namespace std;
int T, n, m;
void solve()
{   
    scanf("%d", &n);
    int res = 0;
    for (int i = 1; i <= n; i ++ )  {
        int x;
        scanf("%d", &x);
        res |= x;
    }
    printf("%d\n", res);
}
int main() {
    scanf("%d", &T);
    while (T -- )   solve();
    return 0;
}

B

#include <bits/stdc++.h>
#define LL long long
using namespace std;
const int N = 2e5 + 10;
int T, n;
int a[N];
void solve()
{   
    scanf("%d", &n);
    int res = 0, maxx = 0;
    for (int i = 1; i <= n; i ++ )  scanf("%d", &a[i]);
    for (int i = 2; i < n; i ++ ) {
        if (a[i] > a[i - 1] && a[i] > a[i + 1]) {
            for (int j = i; j <= min(n, i + 2); j ++ ) 
                a[i + 1] = max(a[i + 1], a[j]);
            res ++;
        }
    }
    printf("%d\n", res);
    for (int i = 1; i <= n; i ++ )  printf("%d ", a[i]);
    printf("\n");
}
int main() {
    scanf("%d", &T);
    while (T -- )   solve();
    return 0;
}

C

#include <bits/stdc++.h>
#define int long long
using namespace std;
const int N = 2e5 + 10;
int T, n;
int a[N];
struct node {
    int x, y, z;
};
void solve()
{   
    scanf("%lld", &n);
    bool flag = 1;
    for (int i = 1; i <= n; i ++ )  scanf("%lld", &a[i]);
    vector<int> v;
    vector<node> ans;
    for (int i = 2; i <= n; i ++ )
        if (a[i] < a[i - 1])
            flag = 0;
    if (flag)   {
        printf("0\n");
        return ;
    }
    int maxx = max(a[n], a[n - 1]);
    if (maxx < 0)   {
        printf("-1\n");
        return;
    }
    v.push_back(a[n]);
    v.push_back(a[n - 1]);
    v.push_back(a[n - 1] - a[n]);
    ans.push_back({n - 2, n - 1, n});
    for (int i = n - 3; i >= 1; i -- ) {
        v.push_back(v.back() - maxx);
        if (maxx == a[n])   ans.push_back({i, i + 1, n});
        else ans.push_back({i, i + 1, n - 1});
    }
    reverse(v.begin(), v.end());
    flag = 1;
    for (int i = 1; i < n; i ++ ) {
        if (v[i] < v[i - 1])
            flag = 0;
    }
    if (!flag) {
        printf("-1\n");
        return;
    }
    printf("%lld\n", (int)ans.size());
    for (auto [x, y, z] : ans)
        cout << x << " " << y << " " << z << endl; 
}
signed main() {
    scanf("%lld", &T);
    while (T -- )   solve();
    return 0;
}

D

#include <bits/stdc++.h>
#define LL long long
using namespace std;
const int N = 2e5 + 10, MOD = 1e9 + 7;
int T, n, p;
int a[N], f[N];
int main() {
    scanf("%d%d", &n, &p);
    f[0] = 1;
    for (int i = 1; i <= p; i ++ ) {
        f[i] = f[i - 1];
        if (i > 1)  f[i] = (f[i] + f[i - 2]) % MOD;
    }
    for (int i = 1; i <= p; i ++) 
        f[i] = (f[i] + f[i - 1]) % MOD;
    
    for (int i = 1; i <= n; i ++ )  scanf("%d", &a[i]);
    sort(a + 1, a + 1 + n);
    set<int> s;
    LL res = 0;
    for (int i = 1; i <= n; i ++ ) {
        bool flag = true;
        int m = a[i];
        while (m) {
            if (s.count(m)) {
                flag = false;
                break;
            }
            if (m % 2 == 1) m /= 2;
            else if (m % 4 == 0) m /= 4;
            else break;
        }
        if (!flag)  continue;
        s.insert(a[i]);
        int b = __lg(a[i]) + 1;
        if (b <= p) res = (res + f[p - b]) % MOD;
    }
    printf("%lld\n", res);
    return 0;
}

E

#include <bits/stdc++.h>
#define LL long long
using namespace std;
const int N = 2e5 + 10, M=  N * 2;
int n, m;
int h[N], op[N], e[M], ne[M], idx;
int a[N], b[N], d[N], q[N], col[N], topo[N];
void add(int a, int b)
{
    e[idx] = b, ne[idx] = h[a], h[a] = idx ++;
}
bool dfs(int u, int c)
{
    col[u] = c;
    for (int i = h[u]; i != -1; i = ne[i]) {
        int j = e[i];
        if (col[j] == -1) {
            if (!dfs(j, c ^ 1))
                return false;
        }
        else if (col[j] == c)   return false;
    }
    return true;
}
bool toposort()
{
    memset(h, -1, sizeof h);
    memset(e, 0, sizeof e);
    memset(ne, 0, sizeof ne);
    idx = 0;
    for (int i = 1; i <= m; i ++ ) {
        if (col[a[i]] == 1)  swap(a[i], b[i]);
        if (op[i] == 1) {
            add(a[i], b[i]), d[b[i]] ++;
            //cout << a[i] << " -> " << b[i] << endl;
        }
        else  {
            add(b[i], a[i]), d[a[i]] ++;
            //cout << b[i] << " -> " << a[i] << endl;
        }
    }
    //for (int i = 1; i <= 4; i ++ )  cout << d[i] << endl;
    int hh = 0, tt = -1;
    for (int i = 1; i <= n; i ++ )
        if (d[i] == 0)  q[++ tt] = i;
    
    int pos = 0;
    while (hh <= tt) {
        int t = q[hh ++ ];
        topo[t] = pos ++;
        for (int i = h[t]; i != -1; i = ne[i]) {
            int j = e[i];
            if (-- d[j] == 0)   
                q[ ++ tt] = j;
        }
    }
    return tt == n - 1;
}
int main() {
    scanf("%d%d", &n, &m);
    memset(h, -1, sizeof h);
    memset(col, -1, sizeof col);
    for (int i = 1; i <= m; i ++ ) {
        scanf("%d%d%d", &op[i], &a[i], &b[i]);
        add(a[i], b[i]), add(b[i], a[i]);
    }
    for (int i = 1; i <= n; i ++ ) {
        if (col[i] == -1) {
            if (!dfs(i, 0)) {
                printf("NO\n");
                return 0;
            }
        }
    }
    if (!toposort()) printf("NO\n");
    else {
        printf("YES\n");
        for (int i = 1; i <= n; i ++ ) 
            cout << (col[i] == 0 ? "L " : "R ") << topo[i] << endl;
    }
    return 0;
}