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Ropewalkers
#include <bits/stdc++.h>
using namespace std;
int a[3], d, ans;
int main()
{
scanf("%d%d%d%d", &a[0], &a[1], &a[2], &d);
sort(a, a + 3);
if (a[1] - a[0] < d)
ans += d - a[1] + a[0];
if (a[2] - a[1] < d)
ans += d - a[2] + a[1];
printf("%d", ans);
}
Email from Polycarp
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = 1e6 + 9;
char s[2][N];
int n;
int main()
{
for (scanf("%d", &n); n--;)
{
scanf("%s%s", s[0], s[1]);
vector<pair<char, int>> v[2];
for (int j = 0; j < 2; ++j)
for (int i = 0, pre = 0; s[j][i]; ++i)
{
if (pre != s[j][i])
v[j].emplace_back(pre = s[j][i], 1);
else
++v[j].back().second;
}
int ans = 1;
if (v[0].size() != v[1].size())
ans = 0;
else
for (int i = 0; ans && i < v[0].size(); ++i)
{
if (v[0][i].first != v[1][i].first)
ans = 0;
if (v[0][i].second > v[1][i].second)
ans = 0;
}
printf(ans ? "YES\n" : "NO\n");
}
}
Exam in BerSU (easy version)
Exam in BerSU (hard version)
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll M = 101;
ll n, m, c, cnt[M];
int main()
{
scanf("%lld%lld", &n, &m);
for (ll i = 0, t; i < n; ++i)
{
scanf("%lld", &t);
for (ll j = c = 0, sum = 0; j < M; ++j)
{
if (sum + j * cnt[j] + t > m)
{
c += (m - t - sum) / j;
break;
}
sum += j * cnt[j], c += cnt[j];
}
++cnt[t];
printf("%lld ", i - c);
}
}
Extra Element
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll N = 2e5 + 9;
pair<ll, ll> p[N];
ll n;
int main()
{
scanf("%lld", &n);
for (ll i = 0; i < n; ++i)
scanf("%lld", &p[i].first), p[i].second = i + 1;
sort(p, p + n);
unordered_set<ll> se;
for (ll i = 1; i < n; ++i)
se.insert(p[i].first - p[i - 1].first);
if (se.size() > 9)
return printf("-1"), 0;
for (auto k : se)
{
ll b = p[0].first, pos = 0;
for (ll i = 0; i < n; ++i)
{
if (!pos)
{
if (k * i + b != p[i].first)
pos = i;
}
else
{
if (k * (i - 1) + b != p[i].first)
{
pos = -1;
break;
}
}
}
if (pos >= 0)
return printf("%lld", p[pos].second), 0;
b = p[1].first - k, pos = 0;
for (ll i = 1; i < n; ++i)
{
if (k * i + b != p[i].first)
{
pos = -1;
break;
}
}
if (pos >= 0)
return printf("%lld", p[pos].second), 0;
}
printf("-1");
}
Polycarp and snakes
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll N = 2047;
char s[N][N];
int t, n, m;
int main()
{
for (scanf("%d", &t); t--;)
{
scanf("%d%d", &n, &m);
vector<int> top(127, n), bot(127, -1), lft(127, m), rht(127, -1);
for (int i = 0; i < n; ++i)
{
scanf("%s", s[i]);
for (int j = 0; s[i][j]; ++j)
{
top[s[i][j]] = min(top[s[i][j]], i);
bot[s[i][j]] = max(bot[s[i][j]], i);
lft[s[i][j]] = min(lft[s[i][j]], j);
rht[s[i][j]] = max(rht[s[i][j]], j);
}
}
int ans = 0;
for (char c = 'a'; ans >= 0 && c <= 'z'; ++c)
if (top[c] < n)
{
if (top[c] != bot[c] && lft[c] != rht[c])
{
ans = -1;
break;
}
ans = c - 'a' + 1;
for (int i = top[c]; ans > 0 && i <= bot[c]; ++i)
for (int j = lft[c]; ans > 0 && j <= rht[c]; ++j)
if (s[i][j] == '.' || s[i][j] < c)
ans = -1;
}
if (ans < 0)
{
printf("NO\n");
continue;
}
printf("YES\n%d\n", ans);
for (char c = 'a'; c < 'a' + ans; ++c)
{
if (top[c] == n)
{
top[c] = top['a' + ans - 1];
bot[c] = bot['a' + ans - 1];
lft[c] = lft['a' + ans - 1];
rht[c] = rht['a' + ans - 1];
}
printf("%d %d %d %d\n", top[c] + 1, lft[c] + 1, bot[c] + 1, rht[c] + 1);
}
}
}
Two Pizzas
#include <bits/stdc++.h>
using namespace std;
const int N = 1 << 9;
vector<tuple<int, int>> v(N, {1e9 + 7, 0});
tuple<int, int, int, int> ans{1, 0, 0, 0};
int n, m, a[N], b[N];
int main()
{
scanf("%d%d", &n, &m);
for (int t, j, s; n--; ++a[s])
for (scanf("%d", &t), s = 0; t--; s |= 1 << j - 1)
scanf("%d", &j);
for (int i = 0; i < N; ++i)
for (int j = i; j; j = i & j - 1)
b[i] += a[j];
for (int i = 1, c, t, j, s; i <= m; ++i)
{
for (scanf("%d%d", &c, &t), s = 0; t--; s |= 1 << j - 1)
scanf("%d", &j);
for (int k = 0; k < N; ++k)
if (get<1>(v[k]))
ans = min(ans, {-b[s | k], c + get<0>(v[k]), get<1>(v[k]), i});
v[s] = min(v[s], {c, i});
}
printf("%d %d", get<2>(ans), get<3>(ans));
}
Playlist for Polycarp (easy version)
Playlist for Polycarp (hard version)
好题。相遇双重DP。
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
struct Mod
{
const ll M;
Mod(ll M) : M(M) {}
ll &qadd(ll &a, ll b) const { return a += b, a < M ? a : (a -= M); }
ll add(ll a, ll b) const { return qadd(a = (a + b) % M, M); }
ll mul(ll a, ll b) const { return add(a * b, M); }
} M(1e9 + 7);
const ll N = 63;
ll n, t, f[N][N][N][4], f1[N][N * N], f23[N][N][N * N];
int main()
{
for (ll i = 0; i < N; ++i)
for (ll j = 0; j < N; ++j)
for (ll k = 0; k < N; ++k)
for (ll g = 0; g < 4; ++g)
{
ll &r = f[i][j][k][g];
if (i + j + k)
{
if (g != 1 && i)
M.qadd(r, M.mul(i, f[i - 1][j][k][1]));
if (g != 2 && j)
M.qadd(r, M.mul(j, f[i][j - 1][k][2]));
if (g != 3 && k)
M.qadd(r, M.mul(k, f[i][j][k - 1][3]));
}
else
r = 1;
}
f1[0][0] = f23[0][0][0] = 1;
scanf("%lld%lld", &n, &t);
for (ll i = 0, x, g; i < n; ++i)
{
scanf("%lld%lld", &x, &g);
if (g == 1)
for (ll s = t; s >= x; --s)
for (ll i = N - 1; i; --i)
M.qadd(f1[i][s], f1[i - 1][s - x]);
else
for (ll s = t; s >= x; --s)
for (ll j = N - 1; g == 2 ? j : ~j; --j)
for (ll k = N - 1; g == 3 ? k : ~k; --k)
M.qadd(f23[j][k][s], f23[j - (g == 2)][k - (g == 3)][s - x]);
}
n = 0;
for (ll s = t; ~s; --s)
for (ll i = N - 1; ~i; --i)
if (f1[i][s])
for (ll j = N - 1; ~j; --j)
for (ll k = N - 1; ~k; --k)
if (f23[j][k][t - s])
M.qadd(n,
M.mul(
f[i][j][k][0],
M.mul(f1[i][s], f23[j][k][t - s])));
printf("%lld", n);
}