oj.uz

Submission #61084

# Submission time Handle Problem Language Result Execution time Memory
61084 2018-07-25T07:47:43 Z ksun48 Election (BOI18_election) C++14
100 / 100
 2031 ms 123956 KB 
#include <bits/stdc++.h>
using namespace std;
typedef long long LL;

int n;
int q;
string s;
vector<int> psums;

const int INF = 1000000000;
const int MAXJ = 20;
vector<int> jumpmin[MAXJ];
vector<int> jumpmax[MAXJ];

vector<int> memo[MAXJ];

void init(){
	for(int b = 0; b < MAXJ; b++){
		jumpmin[b].resize(psums.size());
		jumpmax[b].resize(psums.size());
		if(b == 0){
			for(int i = 0; i < psums.size(); i++){
				jumpmax[b][i] = psums[i];
				jumpmin[b][i] = psums[i];
			}
		} else {
			for(int i = 0; i + (1<<b) <= psums.size(); i++){
				jumpmax[b][i] = max(jumpmax[b-1][i], jumpmax[b-1][i + (1<<(b-1))]);
				jumpmin[b][i] = min(jumpmin[b-1][i], jumpmin[b-1][i + (1<<(b-1))]);
			}
		}
		memo[b].resize(psums.size());
		for(int i = 0; i < psums.size(); i++){
			memo[b][i] = INF;
		}
	}
}

int range_max(int a, int b){
	b++;
	int c = 31 - __builtin_clz(b-a);
	return max(jumpmax[c][a], jumpmax[c][b-(1<<c)]);
}

int range_min(int a, int b){
	b++;
	int c = 31 - __builtin_clz(b-a);
	return min(jumpmin[c][a], jumpmin[c][b-(1<<c)]);
}


// [a,b] in [l,r]

int max_psum(int a, int b, int l, int r, int lv);
int get(int a, int b, int l, int r, int lv){
	if(a != l || b != r) return max_psum(a, b, l, r, lv);
	if(memo[lv][a] == INF){
		memo[lv][a] = max_psum(a, b, l, r, lv);
	}
	return memo[lv][a];
}

int max_psum(int a, int b, int l, int r, int lv){
	if(a == b || b <= l || r <= a) return 0;
	int m = (l + r) / 2;
	if(m == l){
		return max(0, psums[b] - psums[a]);
	}
	if(b <= m){
		return max_psum(a, b, l, m, lv + 1);
	}
	if(m <= a){
		return max_psum(a, b, m, r, lv + 1);
	}
	int ans = 0;
	ans = max(ans, get(a, m, l, m, lv + 1));
	ans = max(ans, get(m, b, m, r, lv + 1));
	ans = max(ans, range_max(m, b) - range_min(a, m));
	return ans;
}

int max_psum_first(int a, int b){
	return max_psum(a, b, 0, n, 0);
}
int main(){
	cin.sync_with_stdio(0); cin.tie(0);
	cin >> n >> s >> q;
	psums.push_back(0);
	for(int i = 0; i < s.size(); i++){
		if(s[i] == 'C'){
			psums.push_back(psums[psums.size() - 1] + 1);
		} else {
			psums.push_back(psums[psums.size() - 1] - 1);
		}
	}
	init();

	for(int i = 0; i < q; i++){
		int l, r;
		cin >> l >> r;
		l--; r--;
		r++;
		int a = max_psum_first(l, r);
		cout << a - (psums[r] - psums[l]) << '\n';
	}
}

Compilation message

election.cpp: In function 'void init()':
election.cpp:22:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for(int i = 0; i < psums.size(); i++){
                   ~~^~~~~~~~~~~~~~
election.cpp:27:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for(int i = 0; i + (1<<b) <= psums.size(); i++){
                   ~~~~~~~~~~~^~~~~~~~~~~~~~~
election.cpp:33:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i = 0; i < psums.size(); i++){
                  ~~^~~~~~~~~~~~~~
election.cpp: In function 'int main()':
election.cpp:89:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < s.size(); i++){
                 ~~^~~~~~~~~~

Subtask #1
28.0 / 28.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 888 KB Output is correct
2 Correct 6 ms 1012 KB Output is correct
3 Correct 5 ms 1012 KB Output is correct
4 Correct 5 ms 1028 KB Output is correct
5 Correct 5 ms 1168 KB Output is correct

Subtask #2
54.0 / 54.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 888 KB Output is correct
2 Correct 6 ms 1012 KB Output is correct
3 Correct 5 ms 1012 KB Output is correct
4 Correct 5 ms 1028 KB Output is correct
5 Correct 5 ms 1168 KB Output is correct
6 Correct 175 ms 18176 KB Output is correct
7 Correct 176 ms 18176 KB Output is correct
8 Correct 132 ms 18176 KB Output is correct
9 Correct 138 ms 18176 KB Output is correct
10 Correct 205 ms 18176 KB Output is correct
11 Correct 218 ms 18244 KB Output is correct
12 Correct 228 ms 18260 KB Output is correct
13 Correct 202 ms 18260 KB Output is correct
14 Correct 147 ms 18260 KB Output is correct
15 Correct 151 ms 18260 KB Output is correct

Subtask #3
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 888 KB Output is correct
2 Correct 6 ms 1012 KB Output is correct
3 Correct 5 ms 1012 KB Output is correct
4 Correct 5 ms 1028 KB Output is correct
5 Correct 5 ms 1168 KB Output is correct
6 Correct 175 ms 18176 KB Output is correct
7 Correct 176 ms 18176 KB Output is correct
8 Correct 132 ms 18176 KB Output is correct
9 Correct 138 ms 18176 KB Output is correct
10 Correct 205 ms 18176 KB Output is correct
11 Correct 218 ms 18244 KB Output is correct
12 Correct 228 ms 18260 KB Output is correct
13 Correct 202 ms 18260 KB Output is correct
14 Correct 147 ms 18260 KB Output is correct
15 Correct 151 ms 18260 KB Output is correct
16 Correct 1772 ms 122984 KB Output is correct
17 Correct 2009 ms 123012 KB Output is correct
18 Correct 1447 ms 123012 KB Output is correct
19 Correct 1231 ms 123012 KB Output is correct
20 Correct 1707 ms 123012 KB Output is correct
21 Correct 1939 ms 123956 KB Output is correct
22 Correct 2013 ms 123956 KB Output is correct
23 Correct 1900 ms 123956 KB Output is correct
24 Correct 2031 ms 123956 KB Output is correct
25 Correct 1942 ms 123956 KB Output is correct