#include <iostream>
using namespace std;
long long a[500005];
long long dp[500005];
const long long inf = -1 * 1e18;
int main ()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
int n;
cin >> n;
for (int i = 0; i < n; i++)
{
cin >> a[i];
dp[i] = inf;
}
dp[0] = 0;
for (int i = 0; i < n; i++)
{
for (int j = i; j >= 0; j--)
{
if (j == 0)
{
if (dp[j] < 0) dp[j] = inf;
else dp[j] = a[i];
continue;
}
if (dp[j] < 0)
{
if (dp[j - 1] == inf) dp[j] = inf;
else dp[j] = dp[j - 1] + a[i];
}
else
{
dp[j] = a[i];
if (dp[j - 1] != inf) dp[j] = max(dp[j], dp[j - 1] + a[i]);
}
if (dp[j] == inf) break;
}
}
for (int i = 0; i < n; i++)
{
if (dp[i] >= 0)
{
cout << i;
return 0;
}
}
cout << -1;
}
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 | #include <iostream> using namespace std; long long a[500005]; long long dp[500005]; const long long inf = -1 * 1e18; int main () { ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0); int n; cin >> n; for (int i = 0; i < n; i++) { cin >> a[i]; dp[i] = inf; } dp[0] = 0; for (int i = 0; i < n; i++) { for (int j = i; j >= 0; j--) { if (j == 0) { if (dp[j] < 0) dp[j] = inf; else dp[j] = a[i]; continue; } if (dp[j] < 0) { if (dp[j - 1] == inf) dp[j] = inf; else dp[j] = dp[j - 1] + a[i]; } else { dp[j] = a[i]; if (dp[j - 1] != inf) dp[j] = max(dp[j], dp[j - 1] + a[i]); } if (dp[j] == inf) break; } } for (int i = 0; i < n; i++) { if (dp[i] >= 0) { cout << i; return 0; } } cout << -1; } |
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