Submission #1331199

#	Time	Username	Problem	Language	Result	Execution time	Memory
1331199		lnt314	Sum Zero (RMI20_sumzero)	C++20	61 / 100	526 ms	75184 KiB

sumzero

// Frozen Forest (")>
#include <bits/stdc++.h>
#define NAME ""
#define ll long long
#define fi first
#define se second
#define vec vector
#define ALL(x) (x).begin(),(x).end()
#define SZ(x) ((int)x.size())
using namespace std;
const int N=4e5+5;
int n,q;
int c[N];
void INIT(){
    cin>>n;
    for(int i=1;i<=n;i++) cin>>c[i];
    cin>>q;
}

const int INF=2e9;
struct ST{
    vec<int> st;
    int n;
    ST(int _n=0){
        n=_n;
        st.assign(n+n+5,INF);
    }
    void upd(int u,int val){
        st[u+=n-1]=val;
        for(u>>=1;u;u>>=1) st[u]=min(st[u<<1],st[u<<1|1]);
    }
    int get(int l,int r){
        int ret=INF;
        for(l+=n-1,r+=n-1;l<=r;l>>=1,r>>=1){
            if(l&1) ret=min(ret,st[l++]);
            if(~r&1) ret=min(ret,st[r--]);
        }
        return ret;
    }
};

vec<ll> ps;
vec<int> cl;
vec<vec<int>> jp;
void SOLVE(){
    ps=vec<ll>(n+5,0);
    cl=vec<int>(n+5,0);
    jp=vec<vec<int>>(n+5,vec<int>(__lg(n)+5,n+1));
    for(int i=1;i<=n;i++) ps[i]=ps[i-1]+c[i];
    map<ll,int> las;
    las[0]=0;
    for(int i=1;i<=n;i++){
        if(las.find(ps[i])!=las.end()){
            int j=las[ps[i]]+1;
            cl[i]=j;
        }
        las[ps[i]]=i;
    }
    ST st(n);
    for(int i=n;i>=0;i--){
        int t=st.get(i+1,n);
        jp[i][0]=(t==INF ? n+1:t);
        if(cl[i]>0) st.upd(cl[i],i);
    }
    for(int j=1;(1<<j)<=n;j++){
        jp[n+1][j-1]=n+1;
        for(int i=0;i<=n;i++){
            jp[i][j]=jp[jp[i][j-1]][j-1]; 
        }
    }
    while(q--){
        int l,r;
        cin>>l>>r;
        int ans=0,u=l-1;
        for(int i=SZ(jp[0])-1;i>=0;i--){
            if(jp[u][i]==0||jp[u][i]>r) continue;
            u=jp[u][i];
            ans+=(1<<i);
        }   
        cout<<ans<<'\n';
    }
}

int main(){
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	if(fopen(NAME ".inp","r")){
		freopen(NAME ".inp","r",stdin);
		freopen(NAME ".out","w",stdout);
	}
	INIT();SOLVE();
}

Compilation message (stderr)

sumzero.cpp: In function 'int main()':
sumzero.cpp:88:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   88 |                 freopen(NAME ".inp","r",stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
sumzero.cpp:89:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   89 |                 freopen(NAME ".out","w",stdout);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 22 / 22
• Subtask 2: 39 / 39
• Subtask 3: 0 / 39