添加 背包理论肌醇01背包 C语言版本

problems/背包理论基础01背包-1.md

@@ -423,5 +423,51 @@ function test () {
 test();
 ```
 
+### C
+```c
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define MAX(a, b) (((a) > (b)) ? (a) : (b))
+#define ARR_SIZE(a) (sizeof((a)) / sizeof((a)[0]))
+#define BAG_WEIGHT 4
+
+void backPack(int* weights, int weightSize, int* costs, int costSize, int bagWeight) {
+    // 开辟dp数组
+    int dp[weightSize][bagWeight + 1];
+    memset(dp, 0, sizeof(int) * weightSize * (bagWeight + 1));
+    
+    int i, j;
+    // 当背包容量大于物品0的重量时，将物品0放入到背包中
+    for(j = weights[0]; j <= bagWeight; ++j) {
+        dp[0][j] = costs[0];
+    }
+
+    // 先遍历物品，再遍历重量
+    for(j = 1; j <= bagWeight; ++j) {
+        for(i = 1; i < weightSize; ++i) {
+            // 如果当前背包容量小于物品重量
+            if(j < weights[i])
+                // 背包物品的价值等于背包不放置当前物品时的价值
+                dp[i][j] = dp[i-1][j];
+            // 若背包当前重量可以放置物品
+            else
+                // 背包的价值等于放置该物品或不放置该物品的最大值
+                dp[i][j] = MAX(dp[i - 1][j],  dp[i - 1][j - weights[i]] + costs[i]);
+        }
+    }
+
+    printf("%d\n", dp[weightSize - 1][bagWeight]);
+}
+
+int main(int argc, char* argv[]) {
+    int weights[] = {1, 3, 4};
+    int costs[] = {15, 20, 30};
+    backPack(weights, ARR_SIZE(weights), costs, ARR_SIZE(costs), BAG_WEIGHT);
+    return 0;
+}
+```
+
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