Submission #1097131

#	Time	Username	Problem	Language	Result	Execution time	Memory
1097131		hgmhc	도넛 (JOI14_ho_t3)	C++17	100 / 100	187 ms	3728 KiB

2014_ho_t3

    #include <bits/stdc++.h>
    #define rep(i,a,b) for (auto i = (a); i <= (b); ++i)
    #define Mup(x,y) x = max(x,y)
    #define mup(x,y) x = min(x,y)
    #define all(x) begin(x),end(x)
    #define per(i,a,b) for (auto i = (b); i >= (a); --i)
    using namespace std;
    using ll = long long;
    using ii = pair<int,int>;
    #define dbg(...) fprintf(stderr,__VA_ARGS__)
     
    const int N = 1e5+3;
    int n, a[2*N];
    ll p[2*N], S;
     
    bool valid(ll l) {
        int s = 1, e = 0;
        ll sum = 0;
        while (s <= n and e < n+n) {
            if (sum < l) {
                sum += a[++e];
            } else {
                int x = e+1, y = n+n, m;
                while (x <= y) {
                    m = (x+y)/2;
                    if (p[m]-p[e] >= sum) y = m-1;
                    else x = m+1;
                }
                if (p[x]-p[e] > 0 and S-(p[x]-p[e])-sum >= sum) {
                    return true;
                }
                
                sum -= a[s++];
            }
        }
        return false;
    }
     
    int main() {
        scanf("%d", &n);
        rep(i,1,n) scanf("%d", &a[i]), p[i] = p[i-1]+a[i], a[i+n] = a[i];
        S = p[n];
        rep(i,n+1,n+n) p[i] = p[i-1]+a[i];
        ll x = 0, y = 1e15, m;
        while (x <= y) {
            m = (x+y)/2;
            if (valid(m)) x = m+1;
            else y = m-1;
        }
        printf("%lld", y);
    }

Compilation message (stderr)

2014_ho_t3.cpp: In function 'int main()':
2014_ho_t3.cpp:40:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   40 |         scanf("%d", &n);
      |         ~~~~~^~~~~~~~~~
2014_ho_t3.cpp:41:25: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   41 |         rep(i,1,n) scanf("%d", &a[i]), p[i] = p[i-1]+a[i], a[i+n] = a[i];
      |                    ~~~~~^~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 15 / 15
• Subtask 3: 30 / 30
• Subtask 4: 50 / 50