Submission #320511

#	Time	Username	Problem	Language	Result	Execution time	Memory
320511		thecodingwizard	Selling RNA Strands (JOI16_selling_rna)	C++11	100 / 100	550 ms	53160 KiB

selling_rna

#include <bits/stdc++.h>

using namespace std;

using ll = long long;
#define ii pair<int, int>
#define f first
#define s second
#define pb push_back
#define mp make_pair
#define all(x) x.begin(), x.end()
#define F0R(i, n) for (int i = 0; i < n; i++)
#define FOR(i, a, b) for (int i = a; i < b; i++)
#define inf 1000000010

#define maxn 100000
int n, m; 
vector<pair<string, int>> A, B;
// query i corresponds to [inA[i], outA[i]] and [inB[i], outB[i]]
int inA[maxn], outA[maxn], inB[maxn], outB[maxn];
vector<int> points[maxn];
ii strings[maxn];
int qryAns[maxn];
// <<x, y>, <i, mult>>
// add mult*(query [x, y]) to qryAns[i]
vector<pair<ii, ii>> queries[maxn];

ii findRange(vector<pair<string, int>> &list, string s) {
    ii res = mp(-1, -1);
    for (int i = 0; i < (int)list.size(); i++) {
        if (list[i].f.rfind(s, 0) == 0) {
            res.s = i;
            if (res.f == -1) res.f = i;
        }
    }
    return res;
}

void calcInOut(vector<pair<string, int>> &A, vector<pair<string, int>> &prefixes, int* inA, int* outA) {
    int curPrefixIndex = 0;
    stack<int> activePrefixes;
    F0R(i, n) {
        while (!activePrefixes.empty() && A[i].f.rfind(prefixes[activePrefixes.top()].f, 0) != 0) {
            outA[prefixes[activePrefixes.top()].s] = i-1; activePrefixes.pop();
        }
        while (curPrefixIndex < m && A[i].f.rfind(prefixes[curPrefixIndex].f, 0) == 0) {
            inA[prefixes[curPrefixIndex].s] = i;
            activePrefixes.push(curPrefixIndex);
            curPrefixIndex++;
        }
        while (curPrefixIndex < m && prefixes[curPrefixIndex].f < A[i].f) {
            inA[prefixes[curPrefixIndex].s] = outA[prefixes[curPrefixIndex].s] = -1;
            curPrefixIndex++;
        }
        while (curPrefixIndex < m && A[i].f.rfind(prefixes[curPrefixIndex].f, 0) == 0) {
            inA[prefixes[curPrefixIndex].s] = i;
            activePrefixes.push(curPrefixIndex);
            curPrefixIndex++;
        }
    }
    while (!activePrefixes.empty()) {
        outA[prefixes[activePrefixes.top()].s] = n-1;
        activePrefixes.pop();
    }
}

int bit[maxn+10];
void upd(int k, int v) {
    k++;
    if (k <= 0) return;
    while (k <= n+5) {
        bit[k]+=v;
        k += k&-k;
    }
}
int qry(int k) {
    k++;
    if (k <= 0) return 0;
    int s = 0;
    while (k) {
        s += bit[k];
        k -= k&-k;
    }
    return s;
}

int main() {
    cin.tie(0)->sync_with_stdio(0);

    cin >> n >> m;
    F0R(i, n) {
        string s; cin >> s;
        A.pb(mp(s, i));
        reverse(all(s));
        B.pb(mp(s, i));
    }
    sort(all(A));
    sort(all(B));
    F0R(i, n) {
        strings[A[i].s].f = i;
        strings[B[i].s].s = i;
    }
    F0R(i, n) {
        //cout << "a point: " << strings[i].f << ", " << strings[i].s << endl;
        points[strings[i].f].pb(strings[i].s);
    }
    /*
    F0R(i, n) {
        cout << i << ": " << A[i].f << endl;
    }
    F0R(i, n) {
        cout << i << ": " << B[i].f << endl;
    }
    */

    vector<pair<string, string>> qryStrings;
    vector<pair<string, int>> prefixes, suffixes;
    F0R(i, m) {
        string a, b; cin >> a >> b; reverse(all(b));
        qryStrings.pb(mp(a, b));
        prefixes.pb(mp(a, i));
        suffixes.pb(mp(b, i));
    }
    sort(all(prefixes));
    sort(all(suffixes));

    calcInOut(A, prefixes, inA, outA);
    calcInOut(B, suffixes, inB, outB);

    /*
    for (auto x : prefixes) {
        int i = x.s;
        ii prefixRange = mp(inA[i], outA[i]); // findRange(0, a);
        ii suffixRange = mp(inB[i], outB[i]); // findRange(1, b);
        cout << qryStrings[i].f << "; " << qryStrings[i].s << ": [" << prefixRange.f << "," << prefixRange.s << "] and [" << suffixRange.f << "," << suffixRange.s << "]" << endl;
    }
    */

    F0R(i, m) {
        ii prefixRange = mp(inA[i], outA[i]); // findRange(0, a);
        ii suffixRange = mp(inB[i], outB[i]); // findRange(1, b);
        if (prefixRange.f-1 >= 0) queries[prefixRange.f-1].pb(mp(suffixRange, mp(i, -1)));
        if (prefixRange.s >= 0) queries[prefixRange.s].pb(mp(suffixRange, mp(i, 1)));
    }
    
    F0R(i, n) {
        for (int x : points[i]) {
            upd(x, 1);
            //cout << "updating " << x << endl;
        }
        for (auto x : queries[i]) {
            //cout << "adding " << x.s.s << "*[" << x.f.f << "," << x.f.s << "] to " << x.s.f << endl;
            qryAns[x.s.f] += x.s.s*(qry(x.f.s)-qry(x.f.f-1));
        }
    }
    F0R(i, m) cout << qryAns[i] << endl;

    return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 25 / 25
• Subtask 3: 25 / 25
• Subtask 4: 40 / 40