Submission #202854

#	Time	Username	Problem	Language	Result	Execution time	Memory
202854		Mercenary	Fire (JOI20_ho_t5)	C++14	100 / 100	390 ms	59636 KiB

ho_t5

#include<bits/stdc++.h>
#define taskname "A"
#define pb push_back
#define mp make_pair

using namespace std;
const int maxn = 2e5 + 6;
typedef pair<int,int> ii;
typedef long long ll;

ll bit[maxn];
void U(int x , int val){
    assert(x > 0);
    for( ; x < maxn ; x += x & -x)bit[x] += val;
}
ll Q(int x){
    if(x <= 0)return 0;
    ll res = 0;
    for( ; x > 0 ; x &= x - 1)res += bit[x];
    return res;
}

int n , q;
int s[maxn] , pre[maxn] , suf[maxn];
vector<pair<ii,int>> query[maxn];
ll ans[maxn];
vector<ii> f[maxn] , g[maxn];

int main(){
    ios_base::sync_with_stdio(0);cin.tie(0);
    if(fopen(taskname".INP","r")){
        freopen(taskname".INP","r",stdin);
        freopen(taskname".OUT","w",stdout);
    }
    cin >> n >> q;
    for(int i = 1 ; i <= n ; ++i){
        cin >> s[i];
    }
    for(int i = 1 ; i <= q ; ++i){
        int t , l , r;cin >> t >> l >> r;
        query[t].pb(mp(mp(l,r),i));
    }
    vector<int> val;
    for(int i = 1 ; i <= n ; ++i){
        while(val.size() && s[val.back()] <= s[i])val.pop_back();
        if(val.size())pre[i] = val.back();
        else pre[i] = 0;
        val.pb(i);
    }
    val.clear();
    for(int i = n ; i >= 1 ; --i){
        while(val.size() && s[val.back()] < s[i])val.pop_back();
        if(val.size())suf[i] = val.back();
        else suf[i] = n + 1;
        val.pb(i);
    }
    for(int i = 1 ; i <= n ; ++i){
        if(pre[i] == 0 || i - pre[i] > suf[i] - i){
            for(int j = i ; j < suf[i] ; ++j){
                f[j - i].pb(mp(j,s[i]));
                if(pre[i])f[j - pre[i]].pb(mp(j,-s[i]));
            }
        }else{
            for(int j = pre[i] + 1 ; j <= i ; ++j){
                g[i - j].pb(mp(j,s[i]));
                g[suf[i] - j].pb(mp(j,-s[i]));
            }
        }
    }
    for(int i = 0 ; i <= n ; ++i){
        for(auto & c : f[i]){
            U(c.first,c.second);
        }
        for(auto & c : query[i]){
            ans[c.second] += Q(c.first.second) - Q(c.first.first-1);
        }
    }
    fill_n(bit,maxn,0);
    for(int i = 0 ; i <= n ; ++i){
        for(auto & c : g[i]){
            U(c.first,c.second);
        }
        for(auto & c : query[i]){
            ans[c.second] += Q(c.first.second - i) - Q(c.first.first-i-1);
        }
    }
    for(int i = 1 ; i <= q ; ++i)cout << ans[i] << '\n';
}

Compilation message (stderr)

ho_t5.cpp: In function 'int main()':
ho_t5.cpp:32:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
         freopen(taskname".INP","r",stdin);
         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
ho_t5.cpp:33:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
         freopen(taskname".OUT","w",stdout);
         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 1 / 1
• Subtask 2: 6 / 6
• Subtask 3: 7 / 7
• Subtask 4: 6 / 6
• Subtask 5: 80 / 80