File size: 4,091 Bytes
1fd0050 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 | #include <bits/stdc++.h>
using namespace std;
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
long long L, R;
if (!(cin >> L >> R)) return 0;
auto bitlen = [](long long x)->int {
int l = 0;
while (x) { l++; x >>= 1; }
return max(1, l);
};
int lenL = bitlen(L);
int lenR = bitlen(R);
int M = lenR;
vector<vector<pair<int,int>>> adj(1); // 1-indexed
vector<int> indeg(1, 0);
auto addNode = [&]()->int {
adj.emplace_back();
indeg.push_back(0);
return (int)adj.size() - 1;
};
auto addEdge = [&](int u, int v, int w){
adj[u].push_back({v, w});
indeg[v]++;
};
vector<int> tail; // tail[k] = node id representing free tail of length k
function<int(int)> getTail = [&](int k)->int {
if ((int)tail.size() <= k) tail.resize(k + 1, -1);
if (tail[k] != -1) return tail[k];
if (k == 0) {
tail[0] = addNode(); // sink with outdegree 0
return tail[0];
}
int id = addNode();
tail[k] = id;
int child = getTail(k - 1);
addEdge(id, child, 0);
addEdge(id, child, 1);
return id;
};
auto buildRange = [&](int m, int l, int r)->int {
// builds a sub-DAG generating exactly m-bit strings in [l, r]
// returns root node id (state with m bits remaining)
vector<int> memo((m + 1) * 4, -1);
function<int(int,int,int)> dfs = [&](int i, int low, int high)->int {
if (i == 0) return getTail(0);
if (!low && !high) return getTail(i);
int key = (i << 2) | (low << 1) | high;
if (memo[key] != -1) return memo[key];
int id = addNode();
memo[key] = id;
int Lbit = (l >> (i - 1)) & 1;
int Rbit = (r >> (i - 1)) & 1;
if (low && high) {
if (Lbit == Rbit) {
addEdge(id, dfs(i - 1, 1, 1), Lbit);
} else {
addEdge(id, dfs(i - 1, 1, 0), 0);
addEdge(id, dfs(i - 1, 0, 1), 1);
}
} else if (low) {
if (Lbit == 0) {
addEdge(id, dfs(i - 1, 1, 0), 0);
addEdge(id, getTail(i - 1), 1);
} else {
addEdge(id, dfs(i - 1, 1, 0), 1);
}
} else { // high only
if (Rbit == 1) {
addEdge(id, dfs(i - 1, 0, 1), 1);
addEdge(id, getTail(i - 1), 0);
} else {
addEdge(id, dfs(i - 1, 0, 1), 0);
}
}
return id;
};
return dfs(m, 1, 1);
};
int start = addNode();
if (lenL == lenR) {
int n = lenL;
int m = n - 1;
int lbits = (int)(L - (1LL << (n - 1)));
int rbits = (int)(R - (1LL << (n - 1)));
int root = buildRange(m, lbits, rbits);
addEdge(start, root, 1);
} else {
// Left boundary length = lenL
{
int n = lenL;
int m = n - 1;
int lbits = (int)(L - (1LL << (n - 1)));
int rbits = (1 << (n - 1)) - 1;
int root = buildRange(m, lbits, rbits);
addEdge(start, root, 1);
}
// Full internal lengths
for (int n = lenL + 1; n <= lenR - 1; n++) {
int t = getTail(n - 1);
addEdge(start, t, 1);
}
// Right boundary length = lenR
{
int n = lenR;
int m = n - 1;
int lbits = 0;
int rbits = (int)(R - (1LL << (n - 1)));
int root = buildRange(m, lbits, rbits);
addEdge(start, root, 1);
}
}
int nNodes = (int)adj.size() - 1;
cout << nNodes << "\n";
for (int i = 1; i <= nNodes; i++) {
cout << (int)adj[i].size();
for (auto &e : adj[i]) {
cout << " " << e.first << " " << e.second;
}
cout << "\n";
}
return 0;
} |