path: root / Year 2 / Design and analysis of algorithms / Practicum / Exam1 / 2-Shots.cpp


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#include <cstdio>
#include <cmath>
#include <vector>
#include <algorithm>
using namespace std;

int main() {
	int N = 0;
	scanf("%d", &N);
	vector<long> m;
	long temp = 0;
	for (int i = 0; i < N; i++) {
		scanf("%ld", &temp);
		m.push_back(temp);
	}

	int l = 0, r = N - 1;
	long lalc = 0, ralc = 0;
	long tot = 0;
	while (l <= r) {
		if (lalc < ralc)
			lalc += m[l++];
		else
			ralc += m[r--];
		if (lalc == ralc) {
			tot = (l - 1 - r) + N;
		}
	}

	printf("%ld", tot);
}