#include <bits/stdc++.h> #define ll long long int #define pb push_back #define st first #define nd second #define pii pair<int,int> #define mp make_pair #define pll pair<long long,long long> using namespace std; const int nax = 1e6 + 5; ll a[nax]; ll pref[nax]; int n; // from cp algorithms struct FenwickTreeMin { vector<int> bit; int n; const int INF = (int)-1e9; FenwickTreeMin(int n) { this->n = n; bit.assign(n, INF); } FenwickTreeMin(vector<int> a) : FenwickTreeMin(a.size()) { for (size_t i = 0; i < a.size(); i++) update(i, a[i]); } int getmin(int r) { int ret = INF; for (; r >= 0; r = (r & (r + 1)) - 1) ret = max(ret, bit[r]); return ret; } void update(int idx, int val) { for (; idx < n; idx = idx | (idx + 1)) bit[idx] = max(bit[idx], val); } }; int dp[nax]; int main() { ios_base::sync_with_stdio(0); cin.tie(0); cin>>n; for(int i=1;i<=n;i++) cin>>a[i]; for(int i=1;i<=n;i++) pref[i] = pref[i - 1] + a[i]; set<ll> values; for(int i=0;i<=n;i++) values.insert(pref[i]); vector<ll> uni; for(ll akt : values) { uni.pb(akt); } for(int i=0;i<=n;i++) { pref[i] = lower_bound(uni.begin(),uni.end(),pref[i]) - uni.begin(); } dp[0] = 0; FenwickTreeMin drzewko(n + 5); drzewko.update(pref[0], 0); for(int i=1;i<=n;i++) { int cur = pref[i]; int pop = drzewko.getmin(cur); dp[i] = pop + 1; drzewko.update(cur,dp[i]); } if(dp[n] == 0) cout<<-1<<"\n"; else cout<<n - dp[n]<<"\n"; return 0; }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 | #include <bits/stdc++.h> #define ll long long int #define pb push_back #define st first #define nd second #define pii pair<int,int> #define mp make_pair #define pll pair<long long,long long> using namespace std; const int nax = 1e6 + 5; ll a[nax]; ll pref[nax]; int n; // from cp algorithms struct FenwickTreeMin { vector<int> bit; int n; const int INF = (int)-1e9; FenwickTreeMin(int n) { this->n = n; bit.assign(n, INF); } FenwickTreeMin(vector<int> a) : FenwickTreeMin(a.size()) { for (size_t i = 0; i < a.size(); i++) update(i, a[i]); } int getmin(int r) { int ret = INF; for (; r >= 0; r = (r & (r + 1)) - 1) ret = max(ret, bit[r]); return ret; } void update(int idx, int val) { for (; idx < n; idx = idx | (idx + 1)) bit[idx] = max(bit[idx], val); } }; int dp[nax]; int main() { ios_base::sync_with_stdio(0); cin.tie(0); cin>>n; for(int i=1;i<=n;i++) cin>>a[i]; for(int i=1;i<=n;i++) pref[i] = pref[i - 1] + a[i]; set<ll> values; for(int i=0;i<=n;i++) values.insert(pref[i]); vector<ll> uni; for(ll akt : values) { uni.pb(akt); } for(int i=0;i<=n;i++) { pref[i] = lower_bound(uni.begin(),uni.end(),pref[i]) - uni.begin(); } dp[0] = 0; FenwickTreeMin drzewko(n + 5); drzewko.update(pref[0], 0); for(int i=1;i<=n;i++) { int cur = pref[i]; int pop = drzewko.getmin(cur); dp[i] = pop + 1; drzewko.update(cur,dp[i]); } if(dp[n] == 0) cout<<-1<<"\n"; else cout<<n - dp[n]<<"\n"; return 0; } |