Submission #345976

#	Time	Username	Problem	Language	Result	Execution time	Memory
345976		Ruxandra985	Election (BOI18_election)	C++14	82 / 100	3093 ms	162016 KiB

election

#include <bits/stdc++.h>
#define DIMN 500010
using namespace std;
int vi[DIMN] , sp[DIMN] , tt[DIMN] , next_c[DIMN];
map <int , int> mp;
pair <int , int> rmq[20][DIMN];
int srmq[20][DIMN];
vector <int> v[DIMN];
 
int aint[4 * DIMN];
int sol;
 
void build (int nod ,int st,int dr){
    int mid = (st + dr)/2;
    if (st == dr){
 
        aint[nod] = min(0 , vi[st]);
 
        return;
    }
 
    build (2*nod,st,mid);
    build (2*nod+1,mid+1,dr);
 
    aint[nod] = min(aint[2 * nod + 1] , sp[dr] - sp[mid] + aint[2 * nod]);
 
}
 
void query (int nod , int st , int dr , int l , int r){
    int mid = (st + dr)/2;
 
    if (l <= st && dr <= r){ /// sunt in interval bun
        sol = min(sol , aint[nod] + sp[r] - sp[dr]);
 
    }
    else {
 
        if (mid + 1 <= r)
            query(2 * nod + 1 , mid + 1 , dr , l , r);
 
        if (l <= mid)
            query(2 * nod , st , mid , l , r);
 
 
    }
 
 
}
 
int main()
{
    FILE *fin = stdin;
    //FILE *ans = fopen ("idk.in","r");
    FILE *fout = stdout;
    int n, q , i , l , r , nod , j , vecin , maxi , fth , inc = 0;
    char c;
    fscanf (fin,"%d\n",&n);
    for (i = 1 ; i <= n ; i++){
        c=fgetc (fin);
        if (c == 'C')
            vi[i] = 1;
        else vi[i] = -1;
 
        sp[i] = vi[i] + sp[i - 1];
 
    }
    next_c[n + 1] = n + 1;
    for (i = n ; i ; i--){
        if (vi[i] == 1)
            next_c[i] = i;
        else next_c[i] = next_c[i + 1];
    }
 
    for (i = n ; i ; i--){
 
        /// sp[j] - sp[i - 1] = -1
        /// sp[j] = -1 + sp[i - 1]
 
        if (vi[i] == -1){
 
            v[i + 1].push_back(i);
            tt[i] = i + 1;
 
        }
        else {
 
            if (mp[sp[i - 1] - 1] != 0){
                v[mp[sp[i - 1] - 1]].push_back(i); /// intervalul i...chestie are suma -1
                tt[i] = mp[sp[i - 1] - 1];
            }
            else {
                v[n + 1].push_back(i); /// n + 1 = nod fictiv radacina
                tt[i] = n + 1;
            }
 
        }
 
        mp[sp[i]] = i;
 
    }
 
    build (1 , 1 , n);
 
    /// vezi ce valoare dai muchiilor
 
    for (nod = 1 ; nod <= n + 1 ; nod++){ /// nod este tatal
 
        for (j = 0 ; j < v[nod].size() ; j++){
 
            vecin = v[nod][j];
 
            //printf ("%d %d " , vecin , nod);
 
            if (nod - vecin > 1 || (nod - vecin == 1 && vi[nod] == -1))
                srmq[0][vecin] = 1; /// altfel e 0
 
            if (nod - vecin == 1 && vi[vecin] == -1){
 
                rmq[0][vecin] = make_pair(nod , 0);
                //printf ("%d\n", 0);
                continue;
 
            }
 
            sol = DIMN;
            query(1 , 1 , n , vecin , min(n , nod));
 
            if (nod != n + 1){
                rmq[0][vecin] = make_pair(nod , -sol - 1);
                //printf ("%d\n", -sol - 1);
            }
            else {
                rmq[0][vecin] = make_pair(nod , -sol);
                //printf ("%d\n",-sol);
            }
 
        }
 
    }
 
    for (i = 1 ; i < 20 ; i++){
        for (j = 1 ; j <= n ; j++){
 
 
            rmq[i][j].first = rmq[i - 1][rmq[i - 1][j].first].first;
            rmq[i][j].second = max(rmq[i - 1][j].second , rmq[i - 1][rmq[i - 1][j].first].second);
            srmq[i][j] = srmq[i - 1][j] + srmq[i - 1][rmq[i - 1][j].first];
 
        }
    }
 
 
 
    fscanf (fin,"%d",&q);
 
    int correct , mini = DIMN , li , ri;
    int deadd = 0 , ant;
 
    for (int aux = 1 ; aux <= q ; aux++){
 
        fscanf (fin,"%d%d",&l,&r);
 
        /*if (aux == 1597){
            printf ("\n");
            for (int k = l ; k <= r ; k++)
                printf ("%d ", vi[k]);
            printf ("\n");
            printf ("a");
        }*/
 
        li = l;
        ri = r;
 
        maxi = 0;
 
        //if (vi[li] == 1)
        inc = 0;
        //else inc = 0;
        l = next_c[l];
 
        if (l > r){
            deadd = ri - li + 1;
            inc = maxi = 0;
        }
        else {
            deadd = l - li;
 
            while (tt[l] <= r){
 
                if (srmq[0][l]){
                    if (l + 1 != tt[l])
                        maxi = max(maxi - (sp[tt[l] - 1] - sp[l - 1]) , rmq[0][l].second);
                }
                //else {
                  //  maxi = max(maxi - 1 , 0);
                //}
                inc += srmq[0][l];
 
                //printf ("%d ",maxi);
 
                ant = srmq[0][l];
 
                l = tt[l];
 
            }
 
            /*maxi = 0;
            inc = -1;
            for (i = 19 ; i >= 0 ; i--){
 
                fth = rmq[i][l].first;
                if (fth  < r && fth){
                    maxi = max(maxi , rmq[i][l].second);
                    l = fth;
                    inc += (1 << i);
                }
 
            }*/
 
            /// l e < r
 
            if (ant)
                l++;
 
            if (l <= r){
                sol = DIMN;
                query (1 , 1 , n , l , r);
                maxi = max(maxi - ( sp[r] - sp[l - 1] ) , -sol);
            }
 
        }
 
        //fscanf (ans, "%d",&correct);
 
        //maxi = max(maxi , - (sp[ri] - sp[li - 1] + inc));
 
        /*if (correct != inc + maxi + deadd){
            mini = min(mini , ri - li + 1);
            if (ri - li + 1 == 4)
                printf ("%d\n",aux);
        }*/
 
        fprintf (fout,"%d\n",inc + maxi + deadd);
 
    }
    //printf ("%d",mini);
    return 0;
}

Compilation message (stderr)

election.cpp: In function 'int main()':
election.cpp:108:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  108 |         for (j = 0 ; j < v[nod].size() ; j++){
      |                      ~~^~~~~~~~~~~~~~~
election.cpp:55:53: warning: unused variable 'fth' [-Wunused-variable]
   55 |     int n, q , i , l , r , nod , j , vecin , maxi , fth , inc = 0;
      |                                                     ^~~
election.cpp:156:9: warning: unused variable 'correct' [-Wunused-variable]
  156 |     int correct , mini = DIMN , li , ri;
      |         ^~~~~~~
election.cpp:156:19: warning: unused variable 'mini' [-Wunused-variable]
  156 |     int correct , mini = DIMN , li , ri;
      |                   ^~~~
election.cpp:57:12: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   57 |     fscanf (fin,"%d\n",&n);
      |     ~~~~~~~^~~~~~~~~~~~~~~
election.cpp:154:12: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  154 |     fscanf (fin,"%d",&q);
      |     ~~~~~~~^~~~~~~~~~~~~
election.cpp:161:16: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  161 |         fscanf (fin,"%d%d",&l,&r);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~
election.cpp:222:13: warning: 'ant' may be used uninitialized in this function [-Wmaybe-uninitialized]
  222 |             if (ant)
      |             ^~

• Subtask 1: 28 / 28
• Subtask 2: 54 / 54
• Subtask 3: 0 / 18