round_profit instead of round_ct

1 files changed, 14 insertions, 16 deletions

diff --git a/Practical2/checkout.c b/Practical2/checkout.c
index 738aa61..289a50d 100644
--- a/Practical2/checkout.c
+++ b/Practical2/checkout.c
@@ -1,30 +1,28 @@
 #include <stdio.h>
 #include <stdint.h>
 
-uint32_t round_ct(uint32_t cents) {
-    switch (cents % 5) {
-        case 0: return cents;
-        case 1: return cents - 1;
-        case 2: return cents - 2;
-        case 3: return cents + 2;
-        case 4: return cents + 1;
+int8_t round_profit(uint32_t value) {
+    switch (value % 5) {
+        case 0: return 0;
+        case 1: return 1;
+        case 2: return 2;
+        case 3: return -2;
+        case 4: return -1;
     }
 }
 
 int32_t maximum_profit(uint16_t products[], uint16_t n_products, uint8_t dividers) {
-    int32_t profit[n_products+1][dividers+1];
+    int8_t profit[n_products+1][dividers+1];
     uint16_t p, d;
     for (p = 0; p <= n_products; p++) {
         uint32_t sums[p];
         if (p == 0) {
             sums[0] = 0;
         } else {
+            sums[p-1] = products[p-1];
             int16_t i;
-            for (i = p-1; i >= 0; i--) {
-                if (i == p-1)
-                    sums[i] = products[i];
-                else
-                    sums[i] = products[i] + sums[i+1];
+            for (i = p-2; i >= 0; i--) {
+                sums[i] = products[i] + sums[i+1];
             }
         }
 
@@ -32,12 +30,12 @@ int32_t maximum_profit(uint16_t products[], uint16_t n_products, uint8_t divider
             if (p == 0) {
                 profit[p][d] = 0;
             } else if (d == 0) {
-                profit[p][d] = sums[0] - round_ct(sums[0]);
+                profit[p][d] = round_profit(sums[0]);
             } else {
-                int32_t max = profit[p][d-1];
+                int8_t max = profit[p][d-1];
                 uint16_t i;
                 for (i = 0; i < p; i++) {
-                    int32_t try = profit[i][d-1] + sums[i] - round_ct(sums[i]);
+                    int8_t try = profit[i][d-1] + round_profit(sums[i]);
                     if (try > max)
                         max = try;
                 }