Hiệu chỉnh thuật toán trên mảng - Sử dụng hàm cmp thay cho order

v3/algo.h

@@ -1,3 +1,5 @@
+/* (C) Nguyễn Bá Ngọc 2025 */
+
 #ifndef ALGO_H_
 #define ALGO_H_
 
@@ -18,34 +20,34 @@ static inline void vassign(void *dest, void *src, int sz) {
 }
 
 static void insort(void *a, int n, int sz,
-        int (*order)(const void *, const void *)) {
+        int (*cmp)(const void *, const void *)) {
   char v[sz];
   for (int i = 1; i < n; ++i) {
     void *p = a + i * sz;
     vassign(v, p, sz);
     p -= sz;
-    while (p >= a && !order(p, v)) {
+    while (p >= a && cmp(p, v) > 0) {
       vassign(p + sz, p, sz);
       p -= sz;
     }
-    vassign(p +sz, v, sz);
+    vassign(p + sz, v, sz);
   }
 }
 
 static void q2insort(void *a, int n, int sz,
-      int (*order)(const void *, const void *)) {
+      int (*cmp)(const void *, const void *)) {
   if (n < 8) {
-    insort(a, n, sz, order);
+    insort(a, n, sz, cmp);
     return;
   }
   void *left = a, *right = a + (n - 1) * sz,
         *mid = left + ((n - 1) >> 1) * sz;
-  if (!order(left, mid)) {
+  if (cmp(left, mid) > 0) {
     vswap(left, mid, sz);
   }
-  if (!order(mid, right)) {
+  if (cmp(mid, right) > 0) {
     vswap(mid, right, sz);
-    if (!order(left, mid)) {
+    if (cmp(left, mid) > 0) {
       vswap(left, mid, sz);
     }
   }
@@ -54,10 +56,10 @@ static void q2insort(void *a, int n, int sz,
   char v[sz];
   vassign(v, mid, sz);
   do {
-    while (!order(v, left)) {
+    while (cmp(left, v) < 0) {
       left += sz;
     }
-    while (!order(right, v)) {
+    while (cmp(v, right) < 0) {
       right -= sz;
     }
     if (left < right) {
@@ -69,15 +71,15 @@ static void q2insort(void *a, int n, int sz,
       right -= sz;
     }
   } while (left <= right);
-  q2insort(a, (right - a) / sz + 1, sz, order);
-  q2insort(left, n - (left - a) / sz, sz, order);
+  q2insort(a, (right - a) / sz + 1, sz, cmp);
+  q2insort(left, n - (left - a) / sz, sz, cmp);
 }
 
 static void *binsearch(void *key, void *a, int n, int sz,
       int (*cmp)(const void *, const void *)) {
   int l = 0, r = n - 1;
   while (l <= r) {
-    int m = (l + r) / 2;
+    int m = (l + r) >> 1;
     void *p = a + m * sz;
     int tmp = cmp(key, p);
     if (tmp == 0) {
@@ -92,18 +94,56 @@ static void *binsearch(void *key, void *a, int n, int sz,
   return 0;
 }
 
+static void *binsearch_lte(void *key, void *a, int n, int sz,
+      int (*cmp)(const void *, const void *)) {
+  int l = 0, r = n - 1;
+  while (l <= r) {
+    int m = (l + r) >> 1;
+    void *p = a + m * sz;
+    int tmp = cmp(key, p);
+    if (tmp == 0) {
+      return p;
+    }
+    if (tmp > 0) {
+      l = m + 1;
+    } else {
+      r = m - 1;
+    }
+  }
+  return r < 0? 0: a + r * sz;
+}
+
+static void *binsearch_gte(void *key, void *a, int n, int sz,
+      int (*cmp)(const void *, const void *)) {
+  int l = 0, r = n - 1;
+  while (l <= r) {
+    int m = (l + r)  >> 1;
+    void *p = a + m * sz;
+    int tmp = cmp(key, p);
+    if (tmp == 0) {
+      return p;
+    }
+    if (tmp > 0) {
+      l = m + 1;
+    } else {
+      r = m - 1;
+    }
+  }
+  return l >= n? 0: a + l * sz;
+}
+
 #define TOP(i) (((i) - 1) >> 1)
 #define LEFT(i) (((i) << 1) + 1)
 #define RIGHT(i) (((i) << 1) + 2)
 
 static void heap_shift_down(void *a, int n, int sz, int i,
-    int (*order)(const void *, const void *)) {
+    int (*cmp)(const void *, const void *)) {
   for (;;) {
     int lc = LEFT(i), rc = RIGHT(i), top = i;
-    if (lc < n && !order(a + top * sz, a + lc * sz)) {
+    if (lc < n && cmp(a + top * sz, a + lc * sz) > 0) {
       top = lc;
     }
-    if (rc < n && !order(a + top * sz, a + rc * sz)) {
+    if (rc < n && cmp(a + top * sz, a + rc * sz) > 0) {
       top = rc;
     }
     if (top == i) {
@@ -115,28 +155,28 @@ static void heap_shift_down(void *a, int n, int sz, int i,
 }
 
 static void heap_shift_up(void *a, int n, int sz, int i,
-        int (*order)(const void *, const void *)) {
+        int (*cmp)(const void *, const void *)) {
   int top = TOP(i);
-  while (i > 0 && !order(a + top * sz, a + i * sz)) {
+  while (i > 0 && cmp(a + top * sz, a + i * sz) > 0) {
     vswap(a + i * sz, a + top * sz, sz);
     i = top;
     top = TOP(top);
   }
 }
 
 static void heapify(void *a, int n, int sz,
-        int (*order)(const void *, const void *)) {
+        int (*cmp)(const void *, const void *)) {
   for (int i = TOP(n - 1); i >= 0; --i) {
-    heap_shift_down(a, n, sz, i, order);
+    heap_shift_down(a, n, sz, i, cmp);
   }
 }
 
 static void heapsort(void *a, int n, int sz,
-        int (*order)(const void *, const void *)) {
-  heapify(a, n, sz, order);
+        int (*cmp)(const void *, const void *)) {
+  heapify(a, n, sz, cmp);
   for (int i = n - 1; i > 0; --i) {
     vswap(a, a + i * sz, sz);
-    heap_shift_down(a, i, sz, 0, order);
+    heap_shift_down(a, i, sz, 0, cmp);
   }
   char *i = a, *j = a + (n - 1) * sz;
   while (i < j) {
@@ -146,7 +186,7 @@ static void heapsort(void *a, int n, int sz,
   }
 }
 
-#define VHEAPSORT(v, order) heapsort(v->elems, v->size, sizeof(v->elems[0]), order)
-#define VQ2INSORT(v, order) q2insort(v->elems, v->size, sizeof(v->elems[0]), order)
+#define VHEAPSORT(v, cmp) heapsort(v->elems, v->size, sizeof(v->elems[0]), cmp)
+#define VQ2INSORT(v, cmp) q2insort(v->elems, v->size, sizeof(v->elems[0]), cmp)
 
-#endif  // ALGO_H_
+#endif  // ALGO_H_

v3/dlist.h

@@ -1,3 +1,5 @@
+/* (C) Nguyễn Bá Ngọc 2025 */
+
 #ifndef DLIST_H_
 #define DLIST_H_
 

v3/tests/binsearch_ut.c

@@ -19,4 +19,34 @@ int main() {
       binsearch((int[]){-10}, a, n, sizeof(int), icmp) != 0) {
     return 1;
   }
+  int *tmp = binsearch_lte((int[]){7}, a, n, sizeof(int), icmp);
+  if (*tmp != 6) {
+    printf("%d - error\n", *tmp);
+    return 1;
+  }
+  tmp = binsearch_gte((int[]){7}, a, n, sizeof(int), icmp);
+  if (*tmp != 8) {
+    printf("%d - error\n", *tmp);
+    return 1;
+  }
+  tmp = binsearch_lte((int[]){0}, a, n, sizeof(int), icmp);
+  if (tmp) {
+    printf("Error lte\n");
+    return 1;
+  }
+  tmp = binsearch_gte((int[]){11}, a, n, sizeof(int), icmp);
+  if (tmp) {
+    printf("Error gte\n");
+    return 1;
+  }
+  tmp = binsearch_lte((int[]){11}, a, n, sizeof(int), icmp);
+  if (*tmp != 10) {
+    printf("%d - error\n", *tmp);
+    return 1;
+  }
+  tmp = binsearch_gte((int[]){0}, a, n, sizeof(int), icmp);
+  if (*tmp != 1) {
+    printf("%d - error\n", *tmp);
+    return 1;
+  }
 }

v3/tests/dlist_demo_ut.c

@@ -1,3 +1,5 @@
+/* (C) Nguyễn Bá Ngọc 2025 */
+
 #include "dlist.h"
 
 #include <stdio.h>

v3/tests/heap_sort_ut.c

@@ -2,30 +2,30 @@
 
 #include <stdio.h>
 
-int lte(const void *o1, const void *o2) {
+int icmp(const void *o1, const void *o2) {
   const int *v1 = o1, *v2 = o2;
-  return *v1 <= *v2;
+  return *v1 - *v2;
 }
 
-int gte(const void *o1, const void *o2) {
+int icmpr(const void *o1, const void *o2) {
   const int *v1 = o1, *v2 = o2;
-  return *v1 >= *v2;
+  return *v2 - *v1;
 }
 
 int main() {
   int a[] = {3, 1, 2};
   int n = sizeof(a) / sizeof(a[0]);
-  heapsort(a, n, sizeof(int), lte);
+  heapsort(a, n, sizeof(int), icmp);
   for (int i = 0; i < n; ++i) {
-    if (i > 0 && !lte(a + (i - 1), a + i)) {
+    if (i > 0 && icmp(a + (i - 1), a + i) > 0) {
       return 1;
     }
     printf("%d ", a[i]);
   }
   printf("\n");
-  heapsort(a, n, sizeof(int), gte);
+  heapsort(a, n, sizeof(int), icmpr);
   for (int i = 0; i < n; ++i) {
-    if (i > 0 && !gte(a + (i - 1), a + i)) {
+    if (i > 0 && icmpr(a + (i - 1), a + i) > 0) {
       return 1;
     }
     printf("%d ", a[i]);

v3/tests/ivec_sort_ut.c

@@ -7,8 +7,8 @@
 
 VECT_DECL_IMPL(ivec, int)
 
-int lte(const void *o1, const void *o2) {
-  return *((const int *)o1) <= *((const int *)o2);
+int icmp(const void *o1, const void *o2) {
+  return *((const int *)o1) - *((const int *)o2);
 }
 
 int main() {
@@ -17,9 +17,9 @@ int main() {
   for (int i = 0; i < 10; ++i) {
     ivec_append(v, rand());
   }
-  VQ2INSORT(v, lte);
+  VQ2INSORT(v, icmp);
   for (int i = 0; i < v->size; ++i) {
-    if (i > 0 && !lte(v->elems + i - 1, v->elems + i)) {
+    if (i > 0 && icmp(v->elems + i - 1, v->elems + i) > 0) {
       return 1;
     }
   }

v3/tests/q2insort_ut.c

@@ -2,33 +2,41 @@
 
 #include <stdio.h>
 
-int lte(const void *o1, const void *o2) {
+int icmp(const void *o1, const void *o2) {
   const int *v1 = o1, *v2 = o2;
-  return *v1 <= *v2;
+  return *v1 - *v2;
 }
 
-int gte(const void *o1, const void *o2) {
+int icmpr(const void *o1, const void *o2) {
   const int *v1 = o1, *v2 = o2;
-  return *v1 >= *v2;
+  return *v2 - *v1;
 }
 
 int main() {
   int a[] = {3, 1, 2, 9, 3, 2, 7, 10, 21, 22, 35, 21, 1, 3, 2};
   int n = sizeof(a) / sizeof(a[0]);
-  q2insort(a, n, sizeof(int), lte);
+  q2insort(a, n, sizeof(int), icmp);
   for (int i = 0; i < n; ++i) {
-    if (i > 0 && !lte(a + (i - 1), a + i)) {
+    if (i > 0 && icmp(a + (i - 1), a + i) > 0) {
       return 1;
     }
     printf("%d ", a[i]);
   }
   printf("\n");
-  q2insort(a, n, sizeof(int), gte);
+  q2insort(a, n, sizeof(int), icmpr);
   for (int i = 0; i < n; ++i) {
-    if (i > 0 && !gte(a + (i - 1), a + i)) {
+    if (i > 0 && icmpr(a + (i - 1), a + i) > 0) {
       return 1;
     }
     printf("%d ", a[i]);
   }
   printf("\n");
+  int b[10] = {0};
+  int bn = sizeof(b) / sizeof(b[0]);
+  q2insort(b, bn, sizeof(int), icmp);
+  q2insort(b, bn, sizeof(int), icmpr);
+  for (int i = 0; i < bn; ++i) {
+    printf("%d ", b[i]);
+  }
+  printf("\n");
 }