split vector from ui.cHEADmaster

Signed-off-by: Richard Qin <richard.qin.x@gmail.com>

5 files changed, 137 insertions, 30 deletions

diff --git a/lab04/Makefile b/lab04/Makefile
index 15c60c0..a242ff5 100644
--- a/lab04/Makefile
+++ b/lab04/Makefile
@@ -16,7 +16,7 @@ test:
 $(TARGET): $(OBJECTS)
 	$(CC) $(CFLAGS) $(OBJECTS) $(LDLIBS) -o $@
 
-ui.o: matrix.h
+ui.o: matrix.h vector_math.h
 
 %.o: %.c
 	$(CC) $(CFLAGS) -c $< -o $@
diff --git a/lab04/tests/Makefile b/lab04/tests/Makefile
index 93e1d65..ef28bff 100644
--- a/lab04/tests/Makefile
+++ b/lab04/tests/Makefile
@@ -8,7 +8,7 @@ TARGET := test_runner
 
 all: $(TARGET)
 
-$(TARGET): test.c ../container_of.h ../list.h ../vec.h ../polynomial.h ../expression.h ../stack.h ../matrix.h
+$(TARGET): test.c ../container_of.h ../list.h ../vec.h ../polynomial.h ../expression.h ../stack.h ../matrix.h ../vector_math.h
 	$(CC) $(CFLAGS) -I.. test.c $(LDLIBS) -o $@
 
 run: $(TARGET)
diff --git a/lab04/tests/test.c b/lab04/tests/test.c
index b40e7b3..64c3947 100644
--- a/lab04/tests/test.c
+++ b/lab04/tests/test.c
@@ -7,6 +7,7 @@
 #include "matrix.h"
 #include "polynomial.h"
 #include "vec.h"
+#include "vector_math.h"
 
 #include <math.h>
 #include <stdbool.h>
@@ -523,6 +524,56 @@ static bool test_vec_mutation_edges(void)
     return true;
 }
 
+static bool test_vector_math(void)
+{
+    struct vec a, b, result;
+    vec_init(&a, double);
+    vec_init(&b, double);
+    vec_init(&result, double);
+    double left[] = { 1.0, 2.0, 3.0 };
+    double right[] = { 4.0, 5.0, 6.0 };
+    CHECK(vec_append(&a, left, 3));
+    CHECK(vec_append(&b, right, 3));
+    CHECK(vector_add(&result, &a, &b));
+    CHECK(result.size == 3);
+    CHECK(((double *)result.data)[0] == 5.0);
+    CHECK(((double *)result.data)[1] == 7.0);
+    CHECK(((double *)result.data)[2] == 9.0);
+    CHECK(vector_sub(&result, &a, &b));
+    CHECK(((double *)result.data)[0] == -3.0);
+    CHECK(((double *)result.data)[1] == -3.0);
+    CHECK(((double *)result.data)[2] == -3.0);
+    double cosine = 0.0;
+    CHECK(vector_cosine(&a, &b, &cosine));
+    CHECK(fabs(cosine - 0.9746318461970762) < 1e-12);
+
+    CHECK(vector_add(&a, &a, &b));
+    CHECK(((double *)a.data)[0] == 5.0);
+    CHECK(((double *)a.data)[2] == 9.0);
+    CHECK(vector_sub(&b, &a, &b));
+    CHECK(((double *)b.data)[0] == 1.0);
+    CHECK(((double *)b.data)[2] == 3.0);
+
+    double sentinel[] = { 8.0, 9.0 };
+    CHECK(vec_append(&result, sentinel, 2));
+    struct vec short_vector;
+    vec_init(&short_vector, double);
+    CHECK(vec_append(&short_vector, sentinel, 2));
+    CHECK(!vector_add(&result, &a, &short_vector));
+    CHECK(result.size == 5);
+    CHECK(((double *)result.data)[3] == 8.0);
+    CHECK(((double *)result.data)[4] == 9.0);
+    struct vec zero;
+    vec_init(&zero, double);
+    CHECK(!vector_cosine(&zero, &zero, &cosine));
+    vec_destroy(&zero);
+    vec_destroy(&short_vector);
+    vec_destroy(&a);
+    vec_destroy(&b);
+    vec_destroy(&result);
+    return true;
+}
+
 static bool test_list_replace_and_move(void)
 {
     LIST_HEAD(head);
@@ -1364,6 +1415,7 @@ int main(void)
         { "polynomial integral", test_polynomial_integral },
         { "polynomial integral edge cases", test_polynomial_integral_edges },
         { "vec mutation edges", test_vec_mutation_edges },
+        { "vector math", test_vector_math },
         { "list replace and move", test_list_replace_and_move },
         { "polynomial copy and derivative edges",
           test_polynomial_copy_and_derivative_edges },
diff --git a/lab04/ui.c b/lab04/ui.c
index 5b6329e..a9a6019 100644
--- a/lab04/ui.c
+++ b/lab04/ui.c
@@ -6,6 +6,7 @@
 #include "polynomial.h"
 #include "expression.h"
 #include "matrix.h"
+#include "vector_math.h"
 #include "tui.h"
 
 #include <ctype.h>
@@ -897,25 +898,17 @@ static void ui_vector_input(struct vec *destination,
 
 static void ui_vector_binary(struct ui_state *state, bool subtract)
 {
-    if (state->vector_a.size != state->vector_b.size) {
+    bool success = subtract ?
+        vector_sub(&state->vector_result, &state->vector_a, &state->vector_b) :
+        vector_add(&state->vector_result, &state->vector_a, &state->vector_b);
+    if (!success && state->vector_a.size != state->vector_b.size) {
         ui_set_status(state, "错误：两个向量维度不同");
         return;
     }
-
-    struct vec temporary;
-    vec_init(&temporary, double);
-    for (size_t i = 0; i < state->vector_a.size; ++i) {
-        double left = *(const double *)vec_at_const(&state->vector_a, i);
-        double right = *(const double *)vec_at_const(&state->vector_b, i);
-        double value = subtract ? left - right : left + right;
-        if (!vec_push_back(&temporary, &value)) {
-            vec_destroy(&temporary);
-            ui_set_status(state, "错误：内存分配失败");
-            return;
-        }
+    if (!success) {
+        ui_set_status(state, "错误：内存分配失败");
+        return;
     }
-    vec_swap(&state->vector_result, &temporary);
-    vec_destroy(&temporary);
     state->vector_result_kind = UI_VECTOR_RESULT_VALUE;
     ui_set_status(state, "已计算 A %c B", subtract ? '-' : '+');
 }
@@ -926,22 +919,11 @@ static void ui_vector_cosine(struct ui_state *state)
         ui_set_status(state, "错误：两个向量维度不同");
         return;
     }
-
-    double dot = 0.0;
-    double norm_a = 0.0;
-    double norm_b = 0.0;
-    for (size_t i = 0; i < state->vector_a.size; ++i) {
-        double left = *(const double *)vec_at_const(&state->vector_a, i);
-        double right = *(const double *)vec_at_const(&state->vector_b, i);
-        dot += left * right;
-        norm_a += left * left;
-        norm_b += right * right;
-    }
-    if (norm_a == 0.0 || norm_b == 0.0) {
+    if (!vector_cosine(&state->vector_a, &state->vector_b,
+                       &state->vector_cosine)) {
         ui_set_status(state, "错误：零向量无法计算夹角余弦");
         return;
     }
-    state->vector_cosine = dot / (sqrt(norm_a) * sqrt(norm_b));
     state->vector_result_kind = UI_VECTOR_RESULT_COSINE;
     ui_set_status(state, "已计算夹角余弦");
 }
diff --git a/lab04/vector_math.h b/lab04/vector_math.h
new file mode 100644
index 0000000..6359c15
--- /dev/null
+++ b/lab04/vector_math.h
@@ -0,0 +1,73 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* Copyright (C) 2026 Richard Qin */
+
+#ifndef VECTOR_MATH_H
+#define VECTOR_MATH_H
+
+#include <math.h>
+
+#include "vec.h"
+
+/* Real vectors use a double-typed struct vec. Destinations may alias inputs. */
+static inline bool vector_add(struct vec *dst,
+                              const struct vec *lhs,
+                              const struct vec *rhs)
+{
+    if (lhs->size != rhs->size) return false;
+
+    struct vec temporary;
+    vec_init(&temporary, double);
+    if (!vec_resize(&temporary, lhs->size)) return false;
+    double *result = temporary.data;
+    const double *left = lhs->data;
+    const double *right = rhs->data;
+    for (size_t i = 0; i < lhs->size; ++i) {
+        result[i] = left[i] + right[i];
+    }
+    vec_swap(dst, &temporary);
+    vec_destroy(&temporary);
+    return true;
+}
+
+static inline bool vector_sub(struct vec *dst,
+                              const struct vec *lhs,
+                              const struct vec *rhs)
+{
+    if (lhs->size != rhs->size) return false;
+
+    struct vec temporary;
+    vec_init(&temporary, double);
+    if (!vec_resize(&temporary, lhs->size)) return false;
+    double *result = temporary.data;
+    const double *left = lhs->data;
+    const double *right = rhs->data;
+    for (size_t i = 0; i < lhs->size; ++i) {
+        result[i] = left[i] - right[i];
+    }
+    vec_swap(dst, &temporary);
+    vec_destroy(&temporary);
+    return true;
+}
+
+static inline bool vector_cosine(const struct vec *lhs,
+                                 const struct vec *rhs,
+                                 double *result)
+{
+    if (lhs->size != rhs->size) return false;
+
+    double dot = 0.0;
+    double norm_lhs = 0.0;
+    double norm_rhs = 0.0;
+    for (size_t i = 0; i < lhs->size; ++i) {
+        double left = ((const double *)lhs->data)[i];
+        double right = ((const double *)rhs->data)[i];
+        dot += left * right;
+        norm_lhs += left * left;
+        norm_rhs += right * right;
+    }
+    if (norm_lhs == 0.0 || norm_rhs == 0.0) return false;
+    *result = dot / (sqrt(norm_lhs) * sqrt(norm_rhs));
+    return true;
+}
+
+#endif /* VECTOR_MATH_H */