#945. 魔法（magic）

https://sjzezoj.com/submission/69384

S2OJ/945/945.cpp

@@ -0,0 +1,70 @@
+#include <iostream>
+#include <algorithm>
+#include <string>
+#include <vector>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 1e5 + 5;
+
+int n, r, b;
+std::string s;
+std::vector<std::pair<int, int>> st{{0, 0}};
+std::vector<std::vector<int>> ans;
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    cin >> n >> r >> b >> s;
+
+    s = ' ' + s;
+
+    int cnt_r = std::count(s.begin(), s.end(), 'R'),
+        cnt_b = std::count(s.begin(), s.end(), 'B');
+
+    if ((n % (r + b)) || (!r && cnt_r) || (!b && cnt_b) || r && b && (cnt_r % r || cnt_b % b || cnt_r / r != cnt_b / b)) {
+        cout << "NO" << endl;
+
+        exit(EXIT_SUCCESS);
+    }
+
+    cout << "YES" << endl
+         << n / (r + b) << endl;
+
+    // Hack: 9 1 2 RBBBRRBBB
+    //
+    // for (int i = 1; i <= n; i++) {
+    //     if (i % (r + b) == 0) {
+    //         cout << i << endl;
+    //     } else {
+    //         cout << i << ' ';
+    //     }
+    // }
+
+    for (int i = 1; i <= n; i++) {
+        st.emplace_back(i, st.back().second + (s[i] == 'R'));
+
+        if (st.size() > r + b && st.back().second - st[st.size() - r - b - 1].second == r) {
+            std::vector<int> res;
+
+            std::for_each(st.end() - r - b, st.end(), [&](std::pair<int, int> x) { res.emplace_back(x.first); });
+            st.erase(st.end() - r - b, st.end());
+            ans.emplace_back(res);
+        }
+    }
+
+    std::reverse(ans.begin(), ans.end());
+
+    for (auto e : ans) {
+        for (int x : e) {
+            cout << x << ' ';
+        }
+
+        cout << endl;
+    }
+
+    return 0;
+}