Create 1734.c

QUSTOJ/1734.c

@@ -0,0 +1,36 @@
+#include <stdio.h>
+ 
+//Written by Coffee. 判断素数
+int isPrime(int num)
+{
+    if (num == 2 || num == 3)
+    {
+        return 1;
+    }
+    if (num % 6 != 1 && num % 6 != 5)
+    {
+        return 0;
+    }
+    for (int i = 5; i*i <= num; i += 6)
+    {
+        if (num % i == 0 || num % (i+2) == 0)
+        {
+            return 0;
+        }
+    }
+    return 1;
+}
+ 
+int main()
+{
+    int a;
+    scanf("%d",&a);
+    for(int i=2;i<=a/2;i++)
+    {
+        if(isPrime(i)&&isPrime(a-i))
+        {
+            printf("%d=%d+%d\n",a,i,a-i);
+        }
+    }
+    return 0;
+}