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-rw-r--r--092.c45
1 files changed, 45 insertions, 0 deletions
diff --git a/092.c b/092.c
new file mode 100644
index 0000000..8616cf8
--- /dev/null
+++ b/092.c
@@ -0,0 +1,45 @@
+
+
+const int limit = 10000000;
+
+const int squares[10] = { 0, 1, 4, 9, 16, 25, 36, 49, 64, 81 };
+
+int next_chain(int number)
+{
+ int sum = 0;
+ int digit;
+ while(number > 0)
+ {
+ digit = number % 10;
+ number = number / 10;
+ sum += squares[digit];
+ }
+ return sum;
+}
+
+int main()
+{
+ int* numbers = calloc(limit, sizeof(int));
+ int i, count;
+
+ for(i=0; i<limit; i++)
+ numbers[i] = next_chain(i);
+
+ count = 0;
+
+ for(i=1; i<limit; i++)
+ {
+ int next = numbers[i];
+ while(next != 1 && next != 89)
+ next = numbers[next];
+
+ numbers[i] = next;
+ if(next == 89)
+ count++;
+ }
+
+ printf("%d\n", count);
+
+ return 0;
+}
+