传送门
题目描述
圆盘上有 n 个数,起初指针在第一个位置,m 次询问,每次询问回答指针至少移动多少次使得指针所经过的所有数的和 >= x(指针不可反向)
分析
我们假设,最后退出的位置为x,那么x一定在这一圈前缀和最大处或者最大处之前,那么我们减去一圈前缀和最大值,剩下的部分就只能用一整圈的和来弥补,除以一整圈的和,向上取整,最后二分前缀和最大值即可
代码
#pragma GCC optimize(3)
#include <bits/stdc++.h>
#define debug(x) cout<<#x<<":"<<x<<endl;
#define dl(x) printf("%lld\n",x);
#define di(x) printf("%d\n",x);
#define _CRT_SECURE_NO_WARNINGS
#define pb push_back
#define mp make_pair
#define all(x) (x).begin(),(x).end()
#define fi first
#define se second
#define SZ(x) ((int)(x).size())
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> PII;
typedef vector<int> VI;
const int INF = 0x3f3f3f3f;
const int N = 2e5 + 10;
const ll mod= 1000000007;
const double eps = 1e-9;
const double PI = acos(-1);
template<typename T>inline void read(T &a){
char c=getchar();T x=0,f=1;while(!isdigit(c)){
if(c=='-')f=-1;c=getchar();}
while(isdigit(c)){
x=(x<<1)+(x<<3)+c-'0';c=getchar();}a=f*x;}
int gcd(int a,int b){
return (b>0)?gcd(b,a%b):a;}
ll a[N],n,m;
int main(){
int T;
read(T);
while(T--){
read(n),read(m);
ll s = 0;
for(int i = 1;i <= n;i++){
ll d;
read(d);
s += d;
a[i] = max(a[i - 1],s);
}
while(m--){
ll q;
read(q);
if(q <= a[n]){
printf("%d ",(lower_bound(a + 1,a + 1 + n,q) - a - 1));
}
else{
if(s <= 0){
printf("-1 ");
}
else{
ll d = q - a[n];
ll t = (d + s - 1) / s;
q -= t * s;
ll res;
res = t * n + 1ll * (lower_bound(a + 1,a + 1 + n,q) - a - 1);
printf("%lld ",res);
}
}
}
puts("");
}
}
/**
* ┏┓ ┏┓+ +
* ┏┛┻━━━┛┻┓ + +
* ┃ ┃
* ┃ ━ ┃ ++ + + +
* ████━████+
* ◥██◤ ◥██◤ +
* ┃ ┻ ┃
* ┃ ┃ + +
* ┗━┓ ┏━┛
* ┃ ┃ + + + +Code is far away from
* ┃ ┃ + bug with the animal protecting
* ┃ ┗━━━┓ 神兽保佑,代码无bug
* ┃ ┣┓
* ┃ ┏┛
* ┗┓┓┏━┳┓┏┛ + + + +
* ┃┫┫ ┃┫┫
* ┗┻┛ ┗┻┛+ + + +
*/