add a1031

PATAdvanced/1031.c

@@ -0,0 +1,30 @@
+#include <stdio.h>
+#include <string.h>
+
+int main()
+{
+    int N, n1, n2, e;
+    char string[81];
+
+    scanf("%s", string);
+    N = strlen(string);
+
+    /* the math is: n1 = n3; n2 >= n1; n2 + 2n1 = N + 2 */
+    e = ((N % 3) + 2) % 3;
+    n1 = (N + 2 - e) / 3;
+    n2 = n1 + e;
+
+    for(int i = 0; i < n1; i++)
+    {
+        putchar(string[i]);
+        for(int j = 0; j < n2 - 2; j++)
+            if(i < n1 - 1)
+                putchar(' ');
+            else
+                putchar(string[n1 + j]);
+        putchar(string[N - 1 - i]);
+        putchar('\n');
+    }
+
+    return 0;
+}