diff --git a/502_ipo.cpp b/502_ipo.cpp
new file mode 100644
index 0000000..d4ebd77
--- /dev/null
+++ b/502_ipo.cpp
@@ -0,0 +1,46 @@
+#include "test.h"
+
+
+class Solution {
+public:
+    int findMaximizedCapital(int k, int w, vector<int>& profits, vector<int>& capital)
+    {
+        std::multimap<int, int, std::greater<int>> profits2captial;
+        for (auto i = 0u; i < profits.size(); ++i)
+            profits2captial.insert({profits[i], capital[i]});
+
+        while (k > 0)
+        {
+            int oldK = k;
+            for (auto iter = profits2captial.begin(); iter != profits2captial.end(); ++iter)
+            {
+                if (iter->second > w)
+                    continue;
+
+                w += iter->first;
+                profits2captial.erase(iter);
+                --k;
+                break;
+            }
+
+            if (oldK == k)
+                break;
+        }
+
+        return w;
+    }
+};
+
+
+int main()
+{
+    vector<tuple<int, int, vector<int>, vector<int>>> datas = 
+    {
+        {2, 0, {1, 2, 3}, {0, 1, 1}},
+        {1, 0, {1, 2, 3}, {1, 1, 2}},
+    };
+    Solution s;
+    for (auto& data : datas)
+        cout << s.findMaximizedCapital(std::get<0>(data), std::get<1>(data), std::get<2>(data), std::get<3>(data)) << endl;
+    return 0;
+}
diff --git a/Makefile b/Makefile
index b43a8f6..4ff0dc0 100644
--- a/Makefile
+++ b/Makefile
@@ -14,6 +14,7 @@ targets = \
 	13_roman_to_integer.exec\
 	14_longest_common_prefix.exec\
 	15_3_sum.exec\
+	502_ipo.exec\
 
 
 CC = g++
diff --git a/ostream_stdcontainer.h b/ostream_stdcontainer.h
index 5c8c4d4..d7edee7 100644
--- a/ostream_stdcontainer.h
+++ b/ostream_stdcontainer.h
@@ -22,6 +22,8 @@
 #include <list>
 #include <forward_list>
 
+#include <tuple>
+
 #include <iostream>
 
 using std::cout;
diff --git a/test.h b/test.h
index 89ea89f..c60e83e 100644
--- a/test.h
+++ b/test.h
@@ -46,6 +46,8 @@ using std::multiset;
 using std::unordered_set;
 using std::unordered_multiset;
 
+using std::tuple;
+
 using namespace std::placeholders;
 
 #endif