#include <iostream>
#include <vector>
using namespace std;
const int N = 1e5 + 10;
int dp[N];
int from[N];
int s[N], f[N];
int n, m;
string ans_s = "";
int ind(int l, int r, int i) {
while (i <= m && l <= f[i] && f[i] <= r) {
i++;
}
i--;
return i;
}
bool ch(int d) {
dp[0] = 0;
for (int i = 1; i <= n; i++) {
dp[i] = 0;
int x = ind(s[i] - d, s[i], dp[i - 1] + 1);
if (x >= dp[i]) {
dp[i] = x;
from[i] = 1;
}
x = ind(s[i], s[i] + d, dp[i - 1] + 1);
if (x >= dp[i]) {
dp[i] = x;
from[i] = 2;
}
if (i != 1) {
if (s[i - 1] + d <= s[i]) {
x = ind(s[i] - d, s[i - 1] + d, dp[i - 2] + 1);
if (x >= dp[i]) {
dp[i] = x;
from[i] = 3;
}
}
}
}
if (dp[n] < m) return false;
ans_s.clear();
int i = n;
while (i != 0) {
if (from[i] == 1) {
ans_s.push_back('L');
i--;
}
else if (from[i] == 2) {
ans_s.push_back('R');
i--;
}
else if (from[i] == 3) {
ans_s.push_back('L');
ans_s.push_back('R');
i -= 2;
}
}
return true;
}
int main() {
cin >> n >> m;
for (int i = 1; i <= n; i++) {
cin >> s[i];
}
for (int i = 1; i <= m; i++) {
cin >> f[i];
}
int l = 0, r = 1e9 + 10, ans = -1;
while (l <= r) {
int mid = (l + r) / 2;
if (ch(mid)) {
ans = mid;
r = mid - 1;
}
else l = mid + 1;
}
cout << ans << "\n";
if (ans == -1) return 0;
reverse(ans_s.begin(), ans_s.end());
cout << ans_s << "\n";
}
Compilation message
Main.cpp: In function 'int main()':
Main.cpp:80:2: error: 'reverse' was not declared in this scope
80 | reverse(ans_s.begin(), ans_s.end());
| ^~~~~~~
