SP1805 HISTOGRA - Largest Rectangle in a Histogram
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我就是想学个单调栈然后全网都是个蓝题
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连接:
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(字都在注释上)
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
1 #include<iostream> 2 #include<stack> 3 #include<cstdio> 4 #include<cstring> 5 using namespace std; 6 struct s{ 7 long long w; 8 long long h; 9 }; 10 long long high[100100]; 11 stack <s>st; 12 long long n; 13 long long deal(){ 14 long long ans=0; 15 s now; 16 now.w=0; 17 now.h=0; 18 st.push(now);//初始化 19 for(long long i=1;i<=n+1;++i){ //n+1是因为n+1是个零,所以说可以清空栈 20 long long nw=0; 21 if(high[i]>st.top().h)//我们要维护的是一个递增的 22 { 23 now.w=1; 24 now.h=high[i]; 25 st.push(now); 26 } 27 else 28 { 29 30 while(st.top().h>high[i]){//单调栈的特性,一直弹出栈顶 31 nw+=(st.top()).w;//计算宽度的和 32 ans=max(ans,1ll*nw*st.top().h);//计算高 33 st.pop(); 34 } 35 //这些弹出来的矩形不能扔,要和后面的合并 36 st.push((s){nw+1,high[i]});//合并后放入 37 } 38 39 } 40 return ans; 41 } 42 long long main(){ 43 while(scanf("%lld",&n)&&n){ //poj就这样,要读入多个数据 44 for(long long i=1;i<=n;++i){ 45 scanf("%lld",&high[i]); 46 } 47 prlong longf("%lld\n",deal()); 48 memset(high,0,sizeof(high));//记得清零,我因为没清零wa了qwq 49 } 50 return 0; 51 }