add 1 to 5

pset9/1-avg.c

@@ -0,0 +1,15 @@
+#include <stdio.h>
+
+int main(void) {
+  int n;
+  scanf("%i", &n);
+  double arr[n];
+  for (int i = 0; i < n; i++) {
+    scanf("%lf", &arr[i]);
+  }
+  double sum = 0;
+  for (int i = 0; i < n; i++) {
+    sum += arr[i];
+  }
+  printf("%.2lf\n", sum / n);
+}

pset9/2-search-linear.c

@@ -0,0 +1,51 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+int search(const int *arr, const int size, const int query);
+
+int main(void) {
+  int n;
+  scanf("%d", &n);
+  int *arr = malloc(sizeof(int) * n);
+  for (int i = 0; i < n; i++) {
+    scanf("%d", &arr[i]);
+  }
+
+  int m;
+  int tmp;
+  int loc;
+  scanf("%d", &m);
+  for (int i = 0; i < m; i++) {
+    scanf("%d", &tmp);
+    loc = search(arr, n, tmp);
+    if (loc == -1) {
+      printf("NULL\n");
+    } else {
+      if (loc - 1 >= 0) {
+        if (loc + 1 < n) {
+          printf("%d %d\n", arr[loc - 1], arr[loc + 1]);
+        } else {
+          printf("%d\n", arr[loc - 1]);
+        }
+      } else {
+				if (loc + 1 < n) {
+					printf("%d\n", arr[loc + 1]);
+				} else {
+					printf("NULL\n");
+				}
+			}
+    }
+  }
+
+  free(arr);
+  return 0;
+}
+
+int search(const int *arr, const int size, const int query) {
+  for (int i = 0; i < size; i++) {
+    if (arr[i] == query) {
+      return i;
+    }
+  }
+  return -1;
+}

pset9/2-search.c

@@ -0,0 +1,60 @@
+#include <stdio.h>
+
+int maxnum = -2147483648;
+
+void mkhashtable(const int *arr, const int size, int *table);
+void printNum(const int *arr, const int loc, const int size);
+
+int main(void) {
+  int n;
+  scanf("%d", &n);
+  int arr[n];
+  // Initialize array
+  for (int i = 0; i < n; i++) {
+    scanf("%d", &arr[i]);
+    if (arr[i] > maxnum)
+      maxnum = arr[i];
+  }
+
+  int hash[maxnum];
+  mkhashtable(arr, n, hash);
+
+  // Search
+  int m;
+  scanf("%d", &m);
+  int tmp;
+  for (int i = 0; i < m; i++) {
+    scanf("%d", &tmp);
+    if (tmp < 0 || tmp >= maxnum) { // Not in the hash table
+      printf("NULL\n");
+    } else {
+      printNum(arr, hash[tmp], n);
+    }
+  }
+  return 0;
+}
+
+void mkhashtable(const int *arr, const int size, int *table) {
+  // Initialize
+  for (int i = 0; i < maxnum; i++) {
+    table[i] = -1;
+  }
+  // Fill values
+  for (int i = 0; i < size; i++) {
+    table[arr[i]] = i;
+  }
+
+  return;
+}
+
+void printNum(const int *arr, const int loc, const int size) {
+  if (loc == -1) {
+    printf("NULL\n");
+  } else {
+    if (loc - 1 >= 0)
+      printf("%d ", arr[loc - 1]);
+		if (loc + 1 <= size)
+			printf("%d ", arr[loc + 1]);
+    printf("\n");
+  }
+}

pset9/3-sort.c

@@ -0,0 +1,35 @@
+#include <stdio.h>
+
+void swap(int *arr, int l, int r);
+
+int main(void) {
+  int n;
+  scanf("%d", &n);
+
+  int arr[n];
+  for (int i = 0; i < n; i++) {
+    scanf("%d", &arr[i]);
+  }
+
+  /* swap(arr, 0, 1); */
+  // Bubble sort
+  for (int i = 0; i < n; i++) {
+    for (int j = 0; j < n - 1; j++) {
+      if (arr[j] % 2 == 1 && arr[j + 1] % 2 == 0) {
+        swap(arr, j, j + 1);
+      }
+    }
+  }
+
+  for (int i = 0; i < n - 1; i++) {
+    printf("%d ", arr[i]);
+  }
+  printf("%d\n", arr[n - 1]);
+  return 0;
+}
+
+void swap(int *arr, int l, int r) {
+	int tmp = arr[l];
+	arr[l] = arr[r];
+	arr[r] = tmp;
+}

pset9/4-vector.c

@@ -0,0 +1,25 @@
+#include <stdio.h>
+
+int main(void) {
+	int n;
+	scanf("%d", &n);
+	int vec1[n];
+	int vec2[n];
+
+	for (int i = 0; i < 2; i++) {
+		for (int j = 0; j < n; j++) {
+			if (i == 0)
+				scanf("%d", &vec1[j]);
+			else
+				scanf("%d", &vec2[j]);
+		}
+	}
+
+	int sum = 0;
+	for (int i = 0; i < n; i++) {
+		sum += vec1[i] * vec2[i];
+	}
+
+	printf("%d\n", sum);
+	return 0;
+}

pset9/5-greedy.c

@@ -0,0 +1,32 @@
+#include <stdio.h>
+
+int getCash(int n);
+
+int main(void) {
+  int n;
+  scanf("%d", &n);
+
+  getCash(n);
+  return 0;
+}
+
+int getCash(int n) {
+  int cashes[7] = {};
+  int cash_rep[7] = {100, 50, 20, 10, 5, 2, 1};
+
+  while (n) {
+    for (int i = 0; i < 7; i++) {
+      if (n >= cash_rep[i]) {
+        n -= cash_rep[i];
+        cashes[i]++;
+        break;
+      }
+    }
+  }
+
+  for (int i = 0; i < 7; i++) {
+    if (cashes[i])
+      printf("%d:%d\n", cash_rep[i], cashes[i]);
+  }
+  return 1;
+}