Submission #1320297

#	Time	Username	Problem	Language	Result	Execution time	Memory
1320297		kasamchi	Wiring (IOI17_wiring)	C++20	30 / 100	1096 ms	8360 KiB

wiring

#include "wiring.h"
#include <vector>
using namespace std;

long long min_total_length(vector<int> r, vector<int> b) {
	int N = r.size() + b.size();
	int ridx = 0, bidx = 0;
	vector<int> pos = {0}, col = {0};
	while (ridx < r.size() || bidx < b.size()) {
		if (bidx == b.size()) {
			pos.push_back(r[ridx]);
			col.push_back(0);
			ridx++;
		} else if (ridx == r.size()) {
			pos.push_back(b[bidx]);
			col.push_back(1);
			bidx++;
		} else if (r[ridx] < b[bidx]) {
			pos.push_back(r[ridx]);
			col.push_back(0);
			ridx++;
		} else {
			pos.push_back(b[bidx]);
			col.push_back(1);
			bidx++;
		}
	}

	vector<long long> pre(N + 1);
	for (int i = 1; i <= N; i++) {
		pre[i] = pre[i - 1] + pos[i];
	}

	vector<long long> cur(N + 2, (long long)1e18);
	vector<long long> dp(N + 1, (long long)1e18);
	for (int idx = 1; idx <= N; ) {
		int clb = idx, crb = idx;
		while (crb <= N && col[crb] == col[clb]) {
			crb++;
		}
		idx = crb;
		crb--;
		if (clb == 1) {
			continue;
		}

		int prb = clb - 1, plb = prb;
		while (plb >= 1 && col[plb] == col[prb]) {
			plb--;
		}
		plb++;

		for (int c = clb; c <= crb; c++) {
			int psz = prb - plb + 1, csz = c - clb + 1;
			long long sum = 0;
			sum += pre[c] - pre[clb - 1];
			sum -= pre[prb] - pre[plb - 1];
			if (psz <= csz) {
				sum -= (long long)pos[prb] * (csz - psz);
			} else {
				sum += (long long)pos[clb] * (psz - csz);
			}

			if (plb == 1) {
				long long cur = 1;
				dp[c] = min(dp[c], sum);
			} else {
				for (int i = 0; i < psz; i++) {
					int p = plb + i;
					dp[c] = min(dp[c], cur[p] + sum);
					sum += pos[p];
					if (psz - i > csz) {
						sum -= pos[clb];
					} else {
						sum -= pos[prb];
					}
				}
			}

			cur[c] = min(cur[c], dp[c]);
			cur[c + 1] = min(cur[c + 1], dp[c]);
		}
	}
	return dp[N];
}

• Subtask 1: 7 / 7
• Subtask 2: 13 / 13
• Subtask 3: 10 / 10
• Subtask 4: 0 / 25
• Subtask 5: 0 / 45