ACM-ICPC 2018 Xuzhou Division game network
Blog last year recorded over the game experience: damn water problem
One year later, the water problem is not a card, but the problem did not do a few. Level a little bit of progress.
F. Features Track
Meaning of the questions:
Given \ (n-\) state in time (frame) cat, with each state \ (<a, b> \ ) FIG. If the same state occurs in a plurality of successive instants, constitute a movement. Seeking the longest such movement.
Ideas:
Attendance problems, SLT pair the Map * use. Note that state to heavy! ! !
AC Code:
Click View Code
#include<iostream>
#include<cstdio>
#include<map>
#include<vector>
#include<algorithm>
using namespace std;
typedef pair<int, int> pii;
map<pii, int> S;
int id;
const int maxn = 100100;
vector<int> arr[maxn];
int ID(pii a) {
if(S.find(a)!=S.end()) return S[a];
return S[a]=++id;
}
int main() {
int t; cin>>t;
while(t--) {
int n, k, maxid = 0;
scanf("%d", &n);
for(int i=1;i<=n;i++) {
scanf("%d", &k);
while(k--) {
int a, b;
scanf("%d %d", &a, &b);
int id = ID(make_pair(a, b));
arr[id].push_back(i);
// cout<<id<<' '<<i<<endl;
maxid = max(maxid, id);
}
}
int ans = 0;
for(int i=1;i<=maxid;i++) {
if(arr[i].size()==0) continue;
else if(arr[i].size()==1) {
ans = max(ans, 1);
continue;
}
sort(arr[i].begin(), arr[i].end());
unique(arr[i].begin(), arr[i].end()); // 去重!!!
int now = 1;
for(int j=1;j<arr[i].size();j++) {
if(arr[i][j]==arr[i][j-1]+1) {
ans = max(ans, ++now);
} else {
now = 1;
}
}
}
printf("%d\n", ans);
id = 0;
S.clear();
for(int i=1;i<=maxid;i++)
arr[i].clear();
}
return 0;
}
H. Ryuji doesn't want to study
Meaning of the questions:
There \ (n-\) book, respectively, each book \ (a [i] \) of knowledge. Reading from \ (L \) to \ (R & lt \) knowledge can be obtained as \ (a [l] × L + a [l + 1] × (L-1) + ⋯ + a [r-1] × A + 2 [R & lt] \) , where \ (R & lt L = - L +. 1 \) . There are times to ask, ask two types of inquiry 1. \ ([l, r] \ ) knowledge point range. 2. the first \ (b \) book knowledge points instead \ (c \) .
Ideas:
Little bit derived formulas can be found and can maintain a two prefix \ (sum1 [n] = \ sum_ {1} ^ {n} a_i \) and \ (sum2 [n] = \ sum_ {1} ^ {n} ia_i \) , then the \ (ANS [L, R & lt] = (SUM2 [R & lt] -sum2 [-L. 1]) - (NR) (SUM2 [R & lt] -sum2 [-L. 1]) \) , then a tree like array to write out soon.
Note that add
the function should work for the \ (the X-\ the n-Le \) , the situation got started writing less than WA. . . Into a tree line, burst ll once they WA
AC Code:
Fenwick tree writing
#include<iostream>
#include<cstdio>
#define lowbit(x) ((x)&(-x))
using namespace std;
typedef long long ll;
const int maxn = 100100;
ll C1[maxn];
ll C2[maxn];
int n, q;
ll arr[maxn];
void add(ll C[], int x, ll val) {
while(x<=n) {
C[x] += val;
x += lowbit(x);
}
}
ll sum(ll C[], int x) {
ll res = 0;
while(x) {
res += C[x];
x -= lowbit(x);
}
return res;
}
int main() {
cin>>n>>q;
for(int i=1;i<=n;i++) {
ll val;
scanf("%lld", &val);
arr[i] = val;
add(C1, i, val);
add(C2, i, val*(n+1-i));
}
while(q--) {
int op;
ll l, r;
scanf("%d %lld %lld", &op, &l, &r);
if(op==1) {
ll Sum1 = sum(C2, r) - sum(C2, l-1);
ll Sum2 = sum(C1, r) - sum(C1, l-1);
printf("%lld\n", Sum1 - Sum2*(n-r));
} else {
add(C1, l, r-arr[l]);
add(C2, l, (r-arr[l])*(n+1-l));
arr[l] = r;
}
}
return 0;
}
Segment tree writing
Click View Code
#include<cstdio>
#include<iostream>
#include<cstring>
using namespace std;
#define lson rt<<1, l, mid
#define rson rt<<1|1, mid+1, r
#define MID (l+r)>>1
const int maxn = 100010;
typedef long long ll;
ll t1[maxn<<2];
ll t2[maxn<<2];
ll arr[maxn];
int n;
void build(ll t[], bool f, int rt, int l, int r) {
if(l==r) {
if(f)
t[rt] = arr[l];
else
t[rt] = arr[l]*(n+1-l);
return;
}
int mid = MID;
build(t, f, lson);
build(t, f, rson);
t[rt] = t[rt<<1] + t[rt<<1|1];
}
void update(ll t[], int pos, ll val, int rt, int l, int r) {
if(l==r) {
t[rt] += val;
return;
}
int mid = MID;
if(pos<=mid)
update(t, pos, val, lson);
else
update(t, pos, val, rson);
t[rt] = t[rt<<1] + t[rt<<1|1];
}
ll query(ll t[], int L, int R, int rt, int l, int r) {
if(L<=l && R>=r) {
return t[rt];
}
ll ans = 0;
int mid = MID;
if(L<=mid)
ans += query(t, L, R, lson);
if(mid<R)
ans += query(t, L, R, rson);
return ans;
}
int main() {
int q;
scanf("%d %d", &n, &q);
for(int i=1;i<=n;i++) {
scanf("%lld", &arr[i]);
}
build(t1, 1, 1, 1, n);
build(t2, 0, 1, 1, n);
while(q--) {
int op;
ll l, r;
scanf("%d %d %d", &op, &l, &r);
if(op==1) {
ll sum1 = query(t1, l, r, 1, 1, n);
ll sum2 = query(t2, l, r, 1, 1, n);
sum2 -= sum1 * (n-r);
printf("%lld\n", sum2);
} else {
update(t1, l, r-arr[l], 1, 1, n);
update(t2, l, (r-arr[l])*(n+1-l), 1, 1, n);
arr[l] = r;
}
}
return 0;
}