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-rw-r--r--max_product_3num.c42
1 files changed, 42 insertions, 0 deletions
diff --git a/max_product_3num.c b/max_product_3num.c
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+// 628. Maximum Product of Three Numbers
+#include <limits.h>
+#include <math.h>
+#include <stdio.h>
+
+/*
+ * given an integer array 'nums', find three numbers whose product is maximum
+ * and return the maximum product
+ */
+
+int maximumProduct(int *nums, int nums_size) {
+ int min1, min2, max1, max2, max3, num;
+ min1 = min2 = INT_MAX;
+ max1 = max2 = max3 = INT_MIN;
+ for (int i = 0; i < nums_size; i++) {
+ num = nums[i];
+ if (min1 >= num) {
+ min2 = min1;
+ min1 = num;
+ } else if (min2 >= num) {
+ min2 = num;
+ }
+ if (max1 <= num) {
+ max3 = max2;
+ max2 = max1;
+ max1 = num;
+ } else if (max2 <= num) {
+ max3 = max2;
+ max2 = num;
+ } else if (max3 <= num) {
+ max3 = num;
+ }
+ }
+ return fmax(min1 * min2 * max1, max1 * max2 * max3);
+}
+
+int main() {
+ int n1[] = {1, 2, 3}, n2[] = {1, 2, 3, 4}, n3[] = {-1, -2, -3};
+ printf("%d\n", maximumProduct(n1, 3)); // expect: 6
+ printf("%d\n", maximumProduct(n2, 4)); // expect: 24
+ printf("%d\n", maximumProduct(n3, 3)); // expect: -6
+}