AcWing 503. 借教室
原题链接
简单
作者:
Charon_11
,
2021-02-09 23:09:07
,
所有人可见
,
阅读 362
typedef long long LL;
const int N = 1000010;
int n, m;
int r[N], d[N], s[N], t[N];
LL b[N];
bool check(int mid)
{
for (int i = 1; i <= n; i ++ ) b[i] = r[i] - r[i - 1];
for (int i = 1; i <= mid; i ++ )
{
b[s[i]] -= d[i];
b[t[i] + 1] += d[i];
}
for (int i = 1; i <= n; i ++ )
{
b[i] += b[i - 1];
if (b[i] < 0) return true;
}
return false;
}
int main()
{
scanf("%d%d", &n, &m);
for (int i = 1; i <= n; i ++ ) scanf("%d", &r[i]);
for (int i = 1; i <= m; i ++ ) scanf("%d%d%d", &d[i], &s[i], &t[i]);
if (!check(m))
{
puts("0");
return 0;
}
int l = 1, r = m;
while (l < r)
{
int mid = l + r >> 1;
if (check(mid)) r = mid;
else l = mid + 1;
}
printf("-1\n%d\n", r);
return 0;
}