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55 lines
1.2 KiB
C++
55 lines
1.2 KiB
C++
#include <iostream>
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#include <algorithm>
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#include <cmath>
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#include <cstring>
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#include <limits>
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#include <utility>
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using std::cin;
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using std::cout;
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const char endl = '\n';
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const int N = 1005;
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int c, h, b, f[N][N][2], ans = std::numeric_limits<int>::max();
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std::pair<int, int> a[N];
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int main() {
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std::ios::sync_with_stdio(false);
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cin.tie(nullptr);
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memset(f, 0x3f, sizeof(f));
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cin >> c >> h >> b;
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for (int i = 1; i <= c; i++) {
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cin >> a[i].first >> a[i].second;
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}
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std::sort(a + 1, a + 1 + c);
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f[0][c][0] = f[0][c][1] = 0;
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for (int i = 1; i <= c; i++) {
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for (int j = c; j >= i; j--) {
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f[i][j][0] = std::min({
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std::max(f[i - 1][j][0] + a[i].first - a[i - 1].first, a[i].second),
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std::max(f[i][j + 1][1] + a[j + 1].first - a[i].first, a[i].second),
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});
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f[i][j][1] = std::min({
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std::max(f[i - 1][j][0] + a[j].first - a[i - 1].first, a[j].second),
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std::max(f[i][j + 1][1] + a[j + 1].first - a[j].first, a[j].second),
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});
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}
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}
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for (int i = 1; i <= c; i++) {
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ans = std::min(ans, std::min(f[i][i][0], f[i][i][1]) + std::abs(b - a[i].first));
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}
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cout << ans << endl;
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return 0;
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}
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