merge LRA

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

src/util/lp/sparse_vector.h

@@ -0,0 +1,38 @@
+/*
+  Copyright (c) 2017 Microsoft Corporation
+  Author: Lev Nachmanson
+*/
+
+#pragma once
+#include "util/vector.h"
+#include <utility>
+#include "util/debug.h"
+#include "util/lp/lp_utils.h"
+#include "util/lp/lp_settings.h"
+namespace lean {
+
+template <typename T>
+class sparse_vector {
+public:
+    vector<std::pair<unsigned, T>>  m_data;
+    void push_back(unsigned index, T val) {
+        m_data.push_back(std::make_pair(index, val));
+    }
+#ifdef LEAN_DEBUG
+    T operator[] (unsigned i) const {
+        for (auto t : m_data) {
+            if (t.first == i) return t.second;
+        }
+        return numeric_traits<T>::zero();
+    }
+#endif
+    void divide(T const & a) {
+        lean_assert(!lp_settings::is_eps_small_general(a, 1e-12));
+        for (auto & t : m_data) {  t.second /= a; }
+    }
+
+    unsigned size() const {
+        return m_data.size();
+    }
+};
+}