From f134ae040c9245cd4c8a818e8190be44a080b727 Mon Sep 17 00:00:00 2001
From: Murch <murch@murch.one>
Date: Fri, 5 Jan 2024 13:52:02 -0500
Subject: [PATCH] Use while loop instead of for loop

---
 src/wallet/coinselection.cpp | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/src/wallet/coinselection.cpp b/src/wallet/coinselection.cpp
index 88422d325b1cb4..92e76cfe4165ed 100644
--- a/src/wallet/coinselection.cpp
+++ b/src/wallet/coinselection.cpp
@@ -292,8 +292,10 @@ util::Result<SelectionResult> CoinGrinder(std::vector<OutputGroup>& utxo_pool, c
     };
 
     SelectionResult result(selection_target, SelectionAlgorithm::CG);
+    bool is_done = false;
+    while (!is_done) {
     for (size_t curr_try = 0;;) {
-        bool should_shift{false}, should_cut{false}, is_done{false};
+        bool should_shift{false}, should_cut{false};
         // Select `next_utxo`
         OutputGroup& utxo = utxo_pool[next_utxo];
         curr_amount += utxo.GetSelectionAmount();
@@ -302,6 +304,7 @@ util::Result<SelectionResult> CoinGrinder(std::vector<OutputGroup>& utxo_pool, c
         ++curr_try;
         ++next_utxo;
 
+        // EVALUATE the new input set candidate, default to exploring the inclusion branch further, else do exactly one SHIFT or CUT.
         if (curr_amount + lookahead[curr_selection.back()] < selection_target + change_target) {
             // Insufficient funds with lookahead: CUT
             should_cut = true;
@@ -330,21 +333,21 @@ util::Result<SelectionResult> CoinGrinder(std::vector<OutputGroup>& utxo_pool, c
             break;
         }
         if (next_utxo == utxo_pool.size()) {
-            // Reached end of UTXO pool, nothing left to add: CUT
+            // Added UTXO was end of UTXO pool, nothing left to add on inclusion or omission branch: CUT
             should_cut = true;
         }
 
         if (should_cut) {
+            // Redirect to exploring Omission branch of second to last selected UTXO (i.e. deselect last selected UTXO, then SHIFT)
+            should_cut = false;
             deselect_last();
             should_shift  = true;
-            should_cut = false;
         }
 
-
         if (should_shift) {
-            // Set `next_utxo` to one after last selected, deselect last selected UTXO
+            // Set `next_utxo` to one after last selected, then deselect last selected UTXO
             if (curr_selection.empty()) {
-                // Exhausted search space before running into limit
+                // Exhausted search space before running into attempt limit
                 result.SetAlgoCompleted(true);
                 break;
             }
@@ -366,7 +369,6 @@ util::Result<SelectionResult> CoinGrinder(std::vector<OutputGroup>& utxo_pool, c
                 if (curr_selection.empty()) {
                     // Exhausted search space before running into limit
                     is_done = true;
-                    std::cout << "FINISHED SEARCH IN CLONE SKIPPING" << std::endl;
                     result.SetAlgoCompleted(true);
                     break;
                 }
@@ -374,7 +376,6 @@ util::Result<SelectionResult> CoinGrinder(std::vector<OutputGroup>& utxo_pool, c
                 deselect_last();
             }
         }
-        if (is_done) break;
     }
 
     if (best_selection.empty()) {