Codeforces Round #478 C. Valhalla Siege

C. Valhalla Siege

time limit per test

2 seconds

memory limit per test

256 megabytes

input

standard input

output

standard output

Ivar the Boneless is a great leader. He is trying to capture Kattegat from Lagertha. The war has begun and wave after wave Ivar's warriors are falling in battle.

Ivar has $\mathrm{nn warriors,\; he\; places\; them\; on\; a\; straight\; line\; in\; front\; of\; the\; main\; gate,\; in\; a\; way\; that\; the ii-th\; warrior\; stands\; right\; after(i-1)(i-1)-th\; warrior.\; The\; first\; warrior\; leads\; the\; attack.}$

Each attacker can take up to ${\mathrm{aiai arrows\; before\; he\; falls\; to\; the\; ground,\; where aiai is\; the ii-th\; warrior\text{'}s\; strength.}}^{}$

Lagertha orders her warriors to shoot ${\mathrm{kiki arrows\; during\; the ii-th\; minute,\; the\; arrows\; one\; by\; one\; hit\; the\; first\; still\; standing\; warrior.\; After\; all\; Ivar\text{'}s\; warriors\; fall\; and\; all\; the\; currently\; flying\; arrows\; fly\; by,\; Thor\; smashes\; his\; hammer\; and\; all\; Ivar\text{'}s\; warriors\; get\; their\; previous\; strengths\; back\; and\; stand\; up\; to\; fight\; again.\; In\; other\; words,\; if\; all\; warriors\; die\; in\; minute tt,\; they\; will\; all\; be\; standing\; to\; fight\; at\; the\; end\; of\; minute tt.}}^{}$

The battle will last for $\mathrm{qq minutes,\; after\; each\; minute\; you\; should\; tell\; Ivar\; what\; is\; the\; number\; of\; his\; standing\; warriors.}$

Input

The first line contains two integers $\mathrm{nn and qq (1\le n,q\le 2000001\le n,q\le 200000) —\; the\; number\; of\; warriors\; and\; the\; number\; of\; minutes\; in\; the\; battle.}$

The second line contains $\mathrm{nn integers a1,a2,\dots ,ana1,a2,\dots ,an (1\le ai\le 1091\le ai\le 109)\; that\; represent\; the\; warriors\text{'}\; strengths.}$

The third line contains $\mathrm{qq integers k1,k2,\dots ,kqk1,k2,\dots ,kq (1\le ki\le 10141\le ki\le 1014),\; the ii-th\; of\; them\; represents\; Lagertha\text{'}s\; order\; at\; the ii-th\; minute: kiki arrows\; will\; attack\; the\; warriors.}$

Output

Output $\mathrm{qq lines,\; the ii-th\; of\; them\; is\; the\; number\; of\; standing\; warriors\; after\; the ii-th\; minute.}$

Examples

input

Copy

5 5
1 2 1 2 1
3 10 1 1 1

output

3
5
4
4
3

input

4 4
1 2 3 4
9 1 10 6

output

1
4
4
1

Note

In the first example:

• after the 1-st minute, the 1-st and 2-nd warriors die.
• after the 2-nd minute all warriors die (and all arrows left over are wasted), then they will be revived thus answer is 5 — all warriors are alive.
• after the 3-rd minute, the 1-st warrior dies.
• after the 4-th minute, the 2-nd warrior takes a hit and his strength decreases by 1.
• after the 5-th minute, the 2-nd warrior dies.

 这题其实就是一个前缀和二分查找。

 1 #include <cstdio>
 2 #include <algorithm>
 3 #include <vector>
 4 #include <queue>
 5 #include <cstring>
 6 #include <string>
 7 using namespace std;
 8 const int maxn = 2e5 + 10;
 9 long long a[maxn], b[maxn], sum[maxn], sum1[maxn];
10 int main() {
11     long long n, q;
12     while(scanf("%lld%lld", &n, &q) != EOF) {
13         sum[0] = 0;
14         for (long long i = 1 ; i <= n ; i++) {
15             scanf("%lld", &a[i]);
16             sum[i] = sum[i - 1] + a[i];
17         }
18         for (long long i = 1 ; i <= q ; i++) {
19             scanf("%lld", &b[i]);
20         }
21         long long temp = 0, cnt, ret = 0;
22         for (long long i = 1 ; i <= q ; i++) {
23             cnt = upper_bound(sum + 1, sum + n + 1, sum[temp] + b[i] + ret) - sum - 1;
24             ret = a[cnt + 1] - (sum[cnt + 1] - sum[temp] - b[i] - ret);
25             if (ret == a[cnt + 1]) ret = 0;
26             temp = cnt;
27             if (temp == n  )  {
28                 temp = 0;
29                 ret = 0;
30             }
31             printf("%lld\n", n - temp);
32         }
33     }
34     return 0;
35 }

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