Submission #1311241

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Source Code Expand

#include<bits/stdc++.h>

using namespace std;

#define fRead(x)        freopen(x,"r",stdin)
#define fWrite(x)       freopen (x,"w",stdout)

#define LL              long long
#define ULL             unsigned long long
#define ff              first
#define ss              second
#define pb              push_back
#define INF             2e16
#define PI              acos(-1.0)
#define mk              make_pair
#define pii             pair<int,int>
#define pll             pair<LL,LL>


#define min3(a,b,c)     min(a,min(b,c))
#define max3(a,b,c)     max(a,max(b,c))
#define min4(a,b,c,d)   min(a,min(b,min(c,d)))
#define max4(a,b,c,d)   max(a,max(b,max(c,d)))
#define SQR(a)          ((a)*(a))
#define FOR(i,a,b)      for(int i=a;i<=b;i++)
#define ROF(i,a,b)      for(int i=a;i>=b;i--)
#define REP(i,b)        for(int i=0;i<b;i++)
#define MEM(a,x)        memset(a,x,sizeof(a))
#define ABS(x)          ((x)<0?-(x):(x))

#define SORT(v)         sort(v.begin(),v.end())
#define REV(v)          reverse(v.begin(),v.end())


#define FastRead        ios_base::sync_with_stdio(0);cin.tie(nullptr);

LL Right[100005];
LL Left[100005];
int main()
{
    FastRead
    string str;
    cin >> str;
    str.insert(str.begin(), '0');

    LL cnt = 0;
    for(int i = str.size()-1;i>=1;i--){
        Right[i] = cnt;
        if(str[i]=='D')cnt++;
    }
    cnt = 0;
    for(int i = 1;i<str.size();i++){
        Left[i] = cnt;
        if(str[i]=='U')cnt++;
    }
    LL ans = 0;
    for(int i = 1;i<str.size();i++){
        LL lu = Left[i];
        LL lo = (i-1) - lu;
        ans += lu + 2*lo;

        LL rd = Right[i];
        LL ro = (str.size()-1 - i) - rd;
        ans += rd + ro*2;
    }
    cout << ans << "\n";
//    for(int i = 1;i<str.size();i++)cout << Left[i] << " ";
//    cout << endl;
//    for(int i = 1;i<str.size();i++)cout << Right[i] << " ";
}

Submission Info

Judge Result