NKSEQ - Dãy số
Tác giả: happyboy99x
Ngôn ngữ: C++
#include <algorithm>
#include <bitset>
#include <cctype>
#include <cfloat>
#include <climits>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>
#include <functional>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <utility>
#include <vector>
using namespace std;
typedef pair<int, int> ii;
typedef vector<ii> vii;
typedef vector<vii> vvii;
typedef vector<int> vi;
typedef vector<vi> vvi;
#define sz(a) int((a).size())
#define fi first
#define se second
#define pb push_back
#define mp make_pair
#define all(c) (c).begin(), (c).end()
#define tr(c,i) for(typeof((c).begin()) i = (c).begin(), _e = (c).end(); it != _e; ++it)
#define present(c,x) ((c).find(x) != (c).end())
#define cpresent(c,x) (find(all(c),x) != (c).end())
#define rep(i,n) for(int i = 0, _n = (n); i < _n; ++i)
#define repd(i,n) for(int i = (n)-1; i >= 0; --i )
#define fo(i,a,b) for(int i = (a), _b = (b); i <= _b; ++i)
#define fod(i,a,b) for(int i = (a), _b = (b); i >= _b; --i)
#define INF 1000000000
#define N 100005
int a[N], s[N], mnl[N], mxr[N], n; //minLeft, maxRight
int main() {
//freopen( "input.txt", "r", stdin );
//freopen( "output.txt", "w", stdout );
scanf( "%d", &n ); rep(i, n) scanf( "%d", a+i );
repd(i, n) s[i] = s[i+1] + a[i];
int sum = 0; fo(i,1,n-1) mnl[i] = min( mnl[i-1], sum+=a[i-1] );
sum = 0; repd(i,n-1) mxr[i] = max( mxr[i+1], sum+=a[i+1] );
sum = 0; rep(i, n) sum += (s[i] + mnl[i] > 0) && (s[i] - mxr[i] > 0);
printf( "%d\n", sum );
/*rep(i, n) printf( "%d ", s[i] ); putchar(10);
rep(i, n) printf( "%d ", mnl[i] ); putchar(10);
rep(i, n) printf( "%d ", mxr[i] ); putchar(10);*/
return 0;
}