92 lines
2.2 KiB
C++
92 lines
2.2 KiB
C++
#include<iostream>
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#include<cstdio>
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#include<vector>
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using namespace std;
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#define max(a,b) a>b?a:b
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#define min(a,b) a<b?a:b
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struct node
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{
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int sum;
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int m;
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int v;
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}ne,cur;
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vector<node>a,b;
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int main()
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{
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int num,j,n;
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char k;
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while(scanf("%d",&num)!=EOF)
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{
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a.clear();
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b.clear();
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while(num--)
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{
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getchar();
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scanf("%c",&k);
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if(k=='I')
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{
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scanf("%d",&n);
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ne.m=n;
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ne.v=n;
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ne.sum=n;
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if(a.size()==0)
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a.push_back(ne);
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else
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{
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int sz=a.size();
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cur=a[sz-1];
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ne.sum = cur.sum + ne.v;
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ne.m = max(ne.sum,cur.m);
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a.push_back(ne);
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}
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}
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else if(k=='L')
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{
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int sz = a.size() ;
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if(sz)
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{
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cur = a[sz-1] ;
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a.pop_back();
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b.push_back(cur);
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}
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}
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else if(k=='R')
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{
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j = b.size();
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if(j)
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{
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ne=b[j-1];
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b.pop_back();
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ne.sum=ne.v;
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ne.m=ne.v;
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int sz = a.size();
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if(sz==0)
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{
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ne.sum=ne.v;
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ne.m=ne.v;
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a.push_back(ne);
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}
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else
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{
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cur = a[sz-1];
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ne.sum = cur.sum + ne.v;
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ne.m = max(ne.sum,cur.m);
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a.push_back(ne);
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}
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}
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}
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else if(k=='D')
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{
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if(a.size())
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a.pop_back();
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}
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else if(k=='Q')
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{
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scanf("%d",&n);
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printf("%d\n",a[n-1].m);
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}
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}
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}
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return 0;
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}
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