#include "towers.h"
#include <map>
#include <vector>
int n;
std::vector<int> heights;
std::vector<int> heightsc;
std::vector<std::vector<int>> stc;
std::map<int, int> cc;
std::vector<int> invcc;
void init(int N, std::vector<int> H) {
n = N;
for (int i : H) cc[i] = 0;
int cccounter = 0;
for (auto& [x, y] : cc) y = cccounter++, invcc.push_back(x);
heightsc = heights = H;
for (int& i : heightsc) i = cc[i];
stc.push_back(heightsc);
for (int sz = 1; sz < 20; ++sz) {
stc.emplace_back();
for (int i = 0; i + (1 << sz) <= N; ++i) {
stc[sz].push_back(std::max(stc[sz - 1][i], stc[sz - 1][i + (1 << (sz - 1))]));
}
}
}
int rangemax(int l, int r) {
int sz = r - l + 1;
int log = -1;
while (sz) sz >>= 1, ++log;
return invcc[std::max(stc[log][l], stc[log][r - (1 << log) + 1])];
}
bool can_communicate(int x, int y, int interference) {
return rangemax(x, y) >= std::max(heights[x], heights[y]) + interference;
}
int max_towers(int l, int r, int d) {
std::vector<int> dp(n + 10);
dp[l] = 1;
int max = 1;
for (int i = l + 1; i <= r; ++i) {
dp[i] = 1;
for (int j = l; j < i; ++j) {
if (can_communicate(j, i, d)) dp[i] = std::max(dp[i], dp[j] + 1);
}
max = std::max(max, dp[i]);
}
return max;
}
