๐๐ฆ ๐๐น๐ด๐ผ ๐ป ๐ ใ๐๐ผ๐บ๐ฝ๐ฒ๐๐ถ๐๐ถ๐๐ฒ ๐ฃ๐ฟ๐ผ๐ด๐ฟ๐ฎ๐บ๐บ๐ถ๐ป๐ดใ
Photo
#include <bits/stdc++.h>
using namespace std;
#define ll long long
class SegmentTree {
private:
vector<ll> t;
ll n;
void upd(ll i, ll v, ll x, ll s, ll e) {
if (s == e) {
t[x] += v;
} else {
ll m = (s + e) / 2;
if (i <= m) {
upd(i, v, 2 * x, s, m);
} else {
upd(i, v, 2 * x + 1, m + 1, e);
}
t[x] = t[2 * x] + t[2 * x + 1];
}
}
ll qry(ll l, ll r, ll x, ll s, ll e) {
if (r < s || e < l) return 0;
if (l <= s && e <= r) return t[x];
ll m = (s + e) / 2;
ll left = qry(l, r, 2 * x, s, m);
ll right = qry(l, r, 2 * x + 1, m + 1, e);
return left + right;
}
public:
SegmentTree(ll sz) : n(sz) {
t.resize(4 * n, 0);
}
void upd(ll i, ll v) {
upd(i, v, 1, 0, n - 1);
}
ll qry(ll l, ll r) {
return qry(l, r, 1, 0, n - 1);
}
};
vector<ll> solve(ll n, vector<ll>& a, ll q, vector<ll>& qrs) {
vector<ll> res;
SegmentTree st(n);
vector<ll> b = a;
sort(b.begin(), b.end());
unordered_map<ll, ll> mp;
for (ll i = 0; i < n; ++i) mp[b[i]] = i;
auto cnt_inv = [&]() -> ll {
ll inv = 0;
for (ll i = n - 1; i >= 0; --i) {
ll idx = mp[a[i]];
inv += st.qry(0, idx - 1);
st.upd(idx, 1);
}
for (ll i = 0; i < n; ++i) {
st.upd(mp[a[i]], -1);
}
return inv;
};
for (ll x : qrs) {
reverse(a.begin(), a.begin() + x);
res.push_back(cnt_inv());
}
return res;
}
Reverse Inversion โ
๐๐ฆ ๐๐น๐ด๐ผ ๐ป ๐ ใ๐๐ผ๐บ๐ฝ๐ฒ๐๐ถ๐๐ถ๐๐ฒ ๐ฃ๐ฟ๐ผ๐ด๐ฟ๐ฎ๐บ๐บ๐ถ๐ป๐ดใ
Photo
#include <bits/stdc++.h>
using namespace std;
struct ST {
int n;
vector<long long> t, lz;
ST(int sz) {
n = sz;
t.resize(4 * n, 0);
lz.resize(4 * n, 0);
}
void p(int nd, int s, int e) {
if (lz[nd] != 0) {
t[nd] += lz[nd];
if (s != e) {
lz[2 * nd + 1] += lz[nd];
lz[2 * nd + 2] += lz[nd];
}
lz[nd] = 0;
}
}
void ru(int nd, int s, int e, int l, int r, long long v) {
p(nd, s, e);
if (s > r || e < l) return;
if (s >= l && e <= r) {
lz[nd] += v;
p(nd, s, e);
return;
}
int m = (s + e) / 2;
ru(2 * nd + 1, s, m, l, r, v);
ru(2 * nd + 2, m + 1, e, l, r, v);
t[nd] = max(t[2 * nd + 1], t[2 * nd + 2]);
}
long long rq(int nd, int s, int e, int l, int r) {
p(nd, s, e);
if (s > r || e < l) return 0;
if (s >= l && e <= r) return t[nd];
int m = (s + e) / 2;
return max(rq(2 * nd + 1, s, m, l, r), rq(2 * nd + 2, m + 1, e, l, r));
}
void u(int l, int r, long long v) {
ru(0, 0, n - 1, l, r, v);
}
long long q(int l, int r) {
return rq(0, 0, n - 1, l, r);
}
};
long long SkillUpdate(int n, int q, vector<tuple<int, int, int>>& u) {
ST st(n);
vector<long long> mx(q, 0);
for (auto& [l, r, x] : u) {
st.u(l - 1, r - 1, x);
}
for (int i = 0; i < q; i++)
{
auto [l, r, x] = u[i];
st.u(l - 1, r - 1, -x);
mx[i] = st.q(0, n - 1);
st.u(l - 1, r - 1, x);
}
return *min_element(mx.begin(), mx.end());
}
Minimize and Maximumโ
#include <bits/stdc++.h>
using namespace std;
#define ll long long
int main(){
int n;
cin>>n;
vector<int>arr(n);
for(int i=0;i<n;i++)cin>>arr[i];
vector<int>presum(n);
presum[0]=arr[0];
for(int i=1;i<n;i++)presum[i]=presum[i-1]+arr[i];
vector<int>dp(n);
vector<int>val(n);
dp[0]=1;
val[0]=arr[0];
for(int i=1;i<n;i++){
int l=0,h=i;
int ind=0;
while(h>=l){
int mid=(l+h)/2;
int sum= presum[i]- (mid>0?presum[mid-1]:0);
int prev = (mid>0?val[mid-1]:0);
if(sum>=prev){
ind=mid;
l=mid+1;
}
else h=mid-1;
}
if(ind==0){
dp[i]=1;
val[i]=presum[i];
}
else{
dp[i]=dp[ind-1]+1;
val[i]=presum[i]-presum[ind-1];
}
}
cout<<dp.back();
}
Operate the subarrayโ