20250914 baekjoon

code_study/Baekjoon/c/2485.c

@@ -0,0 +1,38 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+int GCD(int a, int b);
+
+int main() {
+    int N;
+    scanf("%d",&N);
+    int* tree = (int*)malloc(sizeof(int)*N);
+    for(int i=0; i<N; i++) scanf("%d", &tree[i]);
+
+    int* diff = (int*)malloc(sizeof(int)*(N-1));
+    for(int i=0; i<N-1; i++) diff[i] = tree[i+1] - tree[i];
+    
+    int gcd = diff[0];
+    for(int i=1; i<N-1; i++) gcd = GCD(diff[i], gcd);
+
+    int result = 0;
+    for(int i=0; i<N-1; i++) {
+        result += diff[i]/gcd - 1;
+    }
+
+    printf("%d\n", result);
+
+    free(tree);
+    free(diff);
+    return 0;
+}
+
+int GCD(int a, int b) {
+    while(b!=0) {
+        int r = a%b;
+        a = b;
+        b = r;
+    }
+
+    return a;
+}