二分+贪心
二分确定最终每个人分到的最大值。
注意二分时的下限要设置为一本书的最大页数，否则这本书永远无法分配，则问题无解。
接着从后往前分配页数，由于贪心地使后面大，所以前面有可能分到0，所以，还需要从后往前使没分到的人从分到的人处拿出一张。
输出格式可能有点坑。WA了很多发。
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| #include<bits/stdc++.h>
using namespace std;
typedef pair<int, int> pii;
#define ll long long
const int INF = 0x3f3f3f3f;
const int maxn = 1e5 + 5;
ll t, m, k;
ll a[505];
bool check(ll x) {
ll sum = 0;
ll cnt = 1;
for (ll i = m; i >= 1; i--) {
if (sum + a[i] <= x)sum += a[i];
else {
cnt++;
sum = a[i];
}
if (cnt > k)return false;
}
return true;
}
stack<ll>vc[505], st;
int main() {
ios::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
cin >> t;
while (t--) {
cin >> m >> k;
ll maxa = 0;
for (ll i = 1; i <= m; i++) {
cin >> a[i];
maxa = max(maxa, a[i]);
}
ll L = maxa, R = 5e9 + 10, mid;
while (L < R) {
mid = (L + R) >> 1;
if (check(mid)) {
R = mid;
}
else {
L = mid + 1;
}
}
ll sum = 0;
ll cnt = 1;
for (ll i = m; i >= 1; i--) {
if (sum + a[i] <= L) {
sum += a[i];
vc[k - cnt + 1].push(a[i]);
}
else {
sum = a[i];
cnt++;
vc[k - cnt + 1].push(a[i]);
}
}
ll now = k - cnt + 1;
ll rest = k - cnt;
while (rest) {
if (!vc[now].empty()) {
st.push(vc[now].top());
vc[now].pop();
rest--;
}
if (vc[now].empty()) {
rest++;
now++;
}
}
ll p = st.size();
while (!st.empty()) {
vc[p].push(st.top());
st.pop();
p--;
}
for (ll i = 1; i <= k; i++) {
while (!vc[i].empty()) {
ll ans = vc[i].top();
vc[i].pop();
if (i == k && vc[i].empty())cout << ans;
else cout << ans << ' ';
}
if (i != k)cout << "/ ";
}
cout << endl;
}
return 0;
}
|
