Codeforces 1279 #Codeforces

1279A.cpp

#include <bits/stdc++.h>
#define ll long long
#define ull unsigned long long
#define Android ios::sync_with_stdio(false), cin.tie(NULL)
#define F(i, n) for(int i=0, _iter_max=n; i<_iter_max; i++)
#define print(s) std::cout << s << std::endl

using namespace std;

void redirect_input() { freopen("./input.txt", "r", stdin); }
void redirect_output() { freopen("./output.txt", "w", stdout); }

const int inf = 0x3f3f3f3f;
const int maxn = 300 + 100;

void solve() {
    ll r, g, b;
    cin >> r >> g >> b;
    if(r < g) swap(r, g);
    if(g < b) swap(g, b);
    if(r < g) swap(r, g);
    // r >= g >= b
    if(r > g + b + 1){
        cout << "NO\n";
    }else{
        cout << "YES\n";
    }
}

signed main() {
    Android;
    int t;
    cin >> t;
    while(t--)
    solve();
}

1279B.cpp

#include <bits/stdc++.h>
#define ll long long
#define ull unsigned long long
#define Android ios::sync_with_stdio(false), cin.tie(NULL)
#define F(i, n) for(int i=0, _iter_max=n; i<_iter_max; i++)
#define print(s) std::cout << s << std::endl

using namespace std;

void redirect_input() { freopen("./input.txt", "r", stdin); }
void redirect_output() { freopen("./output.txt", "w", stdout); }

const int inf = 0x3f3f3f3f;
const int maxn = 1e5 + 100;
ll a[maxn], presum[maxn];

void solve() {
    ll n, s;
    cin >> n >> s;
    a[0] = presum[0] = 0;
    int best = 0, skip = 0;
    for(int i=1; i<=n; i++) cin >> a[i];
    for(int i=1; i<=n; i++) presum[i] = presum[i-1] + a[i];
    for(int i=0; i<=n; i++){
        int l = 0, r = n, mid, ans=0;
        while(l <= r){
            mid = (l + r) >> 1;
            if(presum[mid] <= s + a[i]){
                ans = max(ans, mid);
                l = mid + 1;
            }else{
                r = mid - 1;
            }
        }
        if(i > mid) break;
        if(best < ans) best = ans, skip = i;
    }
    cout << skip << '\n';
}

signed main() {
    Android;
    int t;
    cin >> t;
    while(t--)
    solve();
}

1279C.cpp

#include <bits/stdc++.h>
#define ll long long
#define ull unsigned long long
#define Android ios::sync_with_stdio(false), cin.tie(NULL)
#define F(i, n) for(int i=0, _iter_max=n; i<_iter_max; i++)
#define print(s) std::cout << s << std::endl

using namespace std;

void redirect_input() { freopen("./input.txt", "r", stdin); }
void redirect_output() { freopen("./output.txt", "w", stdout); }

const int inf = 0x3f3f3f3f;
const int maxn = 1e5 + 100;

void solve() {
    int n, m;
    cin >> n >> m;
    vector<int> a(n + 1), pos(n + 1), b(m + 1);
    F(i, n) cin >> a[i], pos[a[i]] = i;
    F(i, m) cin >> b[i];
    ll cost = m, rmost = 0;
    F(i, m){
        int p = pos[b[i]];
        if(p > rmost){
            cost += 2 * (p - i);
            rmost = p;
        }
    }
    cout << cost << '\n';
}

signed main() {
    Android;
    int t;
    cin >> t;
    while(t--)
    solve();
}

1279D.cpp

#include <bits/stdc++.h>
#define ll long long
#define ull unsigned long long
#define Android ios::sync_with_stdio(false), cin.tie(NULL)
#define F(i, n) for(int i=0, _iter_max=n; i<_iter_max; i++)
#define print(s) std::cout << s << std::endl
#define pii pair<int, int> 

using namespace std;

void redirect_input() { freopen("./input.txt", "r", stdin); }
void redirect_output() { freopen("./output.txt", "w", stdout); }

const int inf = 0x3f3f3f3f;
const int maxn = 1e6 + 1000;
const ll mod = 998244353;

ll inv(ll val){
    int t = mod - 2;
    ll ret = 1;
    while(t){
        if(t & 1) ret = ret * val % mod;
        t >>= 1;
        val = val * val % mod;
    }
    return ret;
}

int cnt[maxn] = {0};
int gift[maxn] = {0};

void solve() {
    ll n, inv_n, k, v, mx_a = -1;
    cin >> n;
    inv_n = inv(n);
    for(int i=0; i<n; i++){
        cin >> k;
        ll prob = inv_n * inv(k) % mod;
        for(int j=0; j<k; j++){
            cin >> v;
            mx_a = max(mx_a, v);
            gift[v] = (1ll * gift[v] + prob) % mod;
            cnt[v]++;
        }
    }

    for(int i=0; i<=mx_a; i++){
        cnt[i] = cnt[i] * inv_n % mod;
    }
    int ans = 0;
    for(int i=0; i<=mx_a; i++){
        ans = (ans + (1ll * cnt[i] * gift[i]) % mod) % mod;
    }
    cout << ans << '\n';
}

signed main() {
    Android;
    solve();
}