<p v-if="!!prob.preview" v-html="prob.solution"></p>
<p v-else class="problem-time">{{ timestamp2date(prob.added) }}</p>
<div v-show="prob.uid==userid" class="button-group">
<p v-if="!!prob.preview" v-html="prob.solution"></p>
<p v-else class="problem-time">{{ timestamp2date(prob.added) }}</p>
<div v-show="prob.uid==userid" class="button-group">