例題8-10：抄書（二分答案+貪心）

例題8-10：抄書

由於要求有多解時s（1）儘量小，s（1）一樣時s（2）儘量小，採用貪心從後往前找

#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
#include<string>
#include<cmath>
#include<set>
#include<queue>
#include<map>
#include<stack>
#include<vector>
#include<list>
#include<deque>
using namespace std;
typedef long long ll;
const int maxn = 1e6 + 10;
const double eps = 1e-6;
const int INF = 1 << 30;
const int dir[4][2] = {1,0,0,1,0,-1,-1,0};
int T, n, k;
ll a[550], sum, mm;
bool judge(ll x)
{
    ll tot = 0, ans = 1;
    for(int i = 0; i < n; i++)
    {
        if(tot + a[i] <= x)tot+=a[i];
        else tot = a[i],ans++;
        if(ans > k)return false;
    }
    return true;
}
void input()
{
    sum = 0, mm = 0;
    cin >> n >> k;
    for(int i = 0; i < n; i++)
    {
        scanf("%lld", &a[i]);
        mm = max(mm, a[i]);
        sum += a[i];
    }
}
void out(ll x)
{
    //cout<<x<<endl;
    ll tot = 0, ans = 1;
    bool v[550];
    memset(v, 0, sizeof(v));
    for(int i = n - 1; i >= 0; i--)///貪心
    {
        if(tot + a[i] <= x)tot+=a[i];
        else{
            tot = a[i];
            v[i] = 1;
            ans++;
        }
    }
    for(int i = 0; i < n && ans < k; i++)
    {
        if(!v[i])v[i] = 1, ans++;
    }
    for(int i = 0; i < n - 1; i++)
    {
        cout << a[i] << " " ;
        if(v[i])cout<<"/ ";
    }
    cout<<a[n - 1]<<endl;
}
void solve(ll x, ll y)
{
    ll m;
    while(x < y)
    {
        m = (y + x) / 2;
        if(judge(m))y = m;
        else x = m + 1;
    }
    sum = 0;
    ///這裏的答案是x！！！
    out(x);///輸出很複雜；
}
int main()
{
    scanf("%d",&T);
    while(T--)
    {
        input();
        solve(mm, sum);
    }
    return 0;
}