add access.

src/oj/contest/components/ContestType.vue

@@ -0,0 +1,20 @@
+<script setup lang="ts">
+import { Contest } from "~/utils/types"
+import { ContestType } from "~/utils/constants"
+
+interface Props {
+  contest: Contest
+}
+
+const props = defineProps<Props>()
+
+const isPrivate = computed(
+  () => props.contest.contest_type === ContestType.private
+)
+</script>
+
+<template>
+  <n-tag :type="isPrivate ? 'error' : 'default'">
+    {{ isPrivate ? "需要密码" : "公开" }}
+  </n-tag>
+</template>