重构

Author: soulmachine

C++/LeetCodet题解(C++版).pdf

@@ -539,6 +539,31 @@ \subsubsection{代码}
 };
 \end{Code}
 
+\begin{Code}
+// LeetCode, Combinations
+// use prev_permutation()
+class Solution {
+public:
+    vector<vector<int> > combine(int n, int k) {
+        vector<int> values(n);
+        iota(values.begin(), values.end(), 1);
+
+        vector<bool> select(n, false);
+        fill_n(select.begin(), k, true);
+
+        vector<vector<int> > result;
+        do{
+            vector<int> one(k);
+            for (int i = 0, index = 0; i < n; ++i)
+                if (select[i])
+                    one[index++] = values[i];
+            result.push_back(one);
+        } while(prev_permutation(select.begin(), select.end()));
+        return result;
+    }
+};
+\end{Code}
+
 
 \subsubsection{相关题目}
 \begindot