2022.09.16 模拟赛小结（互测）
2022.09.16 模拟赛小结（互测）
题面
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赛时思路
T1
赛时写了个暴力 + 卡时 + 随机化 + 贪心的纯纯乱搞，Luogu 能过一大半的点，不过数据被 zpair 加强之后直接除了暴力分全部寄掉了。
Code
#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
namespace input{
int seed,lst=1;
const int prime1=163337,prime2=998244353;
void init(){
scanf("%d",&seed);
}
int read(){
//return lst=((lst*prime1+seed)%prime2+prime2)%prime2;
}
}
#define PI M_PI
#define E M_E
#define npt nullptr
#define SON i->to
/******************************
abbr
******************************/
using namespace std;
mt19937 rnd(random_device{}());
int rndd(int l, int r){return rnd() % (r - l + 1) + l;}
bool rnddd(int x){return rndd(1, 100) < x;}
typedef unsigned int uint;
typedef unsigned long long unll;
typedef long long ll;
template<typename T = int>
inline T read(void);
int a[6100000];
int N, D;
ll P;
namespace BL{
int ans(0);
int len(0);
ll sum(0);
deque < int > deq;
int Make(void){
for(int i = 1; i <= N - D + 1; ++i){
len = 0;
sum = 0;
deq.clear();
for(int j = 1; j <= N; ++j){
ll val = (j >= i && j <= i + D - 1) ? 0 : a[j];
while(!deq.empty() && sum + val > P)--len, sum -= deq.front(), deq.pop_front();
if(sum + val <= P)deq.push_back(val), sum += val, ++len, ans = max(ans, len);
// printf("%d ", len);
}
// printf("%d\n", ans);
}
return ans;
}
}
int main(){
// freopen("T1.in", "r", stdin);
// freopen("T1.out", "w", stdout);
N = read(); P = read<ll>(); D = read(); //input::init();
for(int i = 1; i <= N; ++i)a[i] = read();
if(N <= 1000){printf("%d\n", BL::Make()); return 0;}
// printf("%d\n", BL::Make());
int ans(0);
ll cur(0);
for(int i = 1; i <= D - 1; ++i)cur += a[i];
ll maxx(-1), maxp;
for(int i = 1; i <= N - D + 1; ++i){
cur -= a[i - 1], cur += a[i + D - 1];
if(cur > maxx){
maxx = cur;
maxp = i;
}
}
// printf("%d\n", maxp);
// for(int i = maxp; i <= maxp + D - 1; ++i)
deque < int > deq;
int len = 0;
int sum = 0;
deq.clear();
for(int j = 1; j <= N; ++j){
// printf("Caling p = %d\n", maxp);
ll val = (j >= maxp && j <= maxp + D - 1) ? 0 : a[j];
while(!deq.empty() && sum + val > P)--len, sum -= deq.front(), deq.pop_front();
if(sum + val <= P)deq.push_back(val), sum += val, ++len, ans = max(ans, len);
// printf("%d ", len);
}
int pos(0);
while((double)clock() / CLOCKS_PER_SEC < 0.3){
pos = 0;
while(pos < 1 || pos > N - D + 1)pos = maxp - rndd(1, D - 1);
// printf("Caling p = %d\n", pos);
len = 0;
sum = 0;
deq.clear();
for(int j = 1; j <= N; ++j){
ll val = (j >= pos && j <= pos + D - 1) ? 0 : a[j];
while(!deq.empty() && sum + val > P)--len, sum -= deq.front(), deq.pop_front();
if(sum + val <= P)deq.push_back(val), sum += val, ++len, ans = max(ans, len);
// printf("%d ", len);
}
}
while((double)clock() / CLOCKS_PER_SEC < 0.5){
pos = 0;
while(pos < 1 || pos > N - D + 1)pos = int((double)maxp * ((double)rndd(1, 100) / 100) * (rnddd(50) ? 1 : -1));
// printf("Caling p = %d\n", pos);
len = 0;
sum = 0;
deq.clear();
for(int j = 1; j <= N; ++j){
ll val = (j >= pos && j <= pos + D - 1) ? 0 : a[j];
while(!deq.empty() && sum + val > P)--len, sum -= deq.front(), deq.pop_front();
if(sum + val <= P)deq.push_back(val), sum += val, ++len, ans = max(ans, len);
}
}
while((double)clock() / CLOCKS_PER_SEC < 0.7){
pos = rndd(1, N - D + 1);
// printf("Caling p = %d\n", pos);
len = 0;
sum = 0;
deq.clear();
for(int j = 1; j <= N; ++j){
ll val = (j >= pos && j <= pos + D - 1) ? 0 : a[j];
while(!deq.empty() && sum + val > P)--len, sum -= deq.front(), deq.pop_front();
if(sum + val <= P)deq.push_back(val), sum += val, ++len, ans = max(ans, len);
// printf("%d ", len);
}
}
printf("%d\n", ans);
fprintf(stderr, "Time: %.6lf\n", (double)clock() / CLOCKS_PER_SEC);
return 0;
}
template<typename T>
inline T read(void){
T ret(0);
short flag(1);
char c = getchar();
while(c != '-' && !isdigit(c))c = getchar();
if(c == '-')flag = -1, c = getchar();
while(isdigit(c)){
ret *= 10;
ret += int(c - '0');
c = getchar();
}
ret *= flag;
return ret;
}
T2
写了个奇怪的暴力，写挂了，爆零。
Code
#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
#define PI M_PI
#define E M_E
#define npt nullptr
#define SON i->to
/******************************
abbr
******************************/
using namespace std;
mt19937 rnd(random_device{}());
int rndd(int l, int r){return rnd() % (r - l + 1) + l;}
typedef unsigned int uint;
typedef unsigned long long unll;
typedef long long ll;
#define getchar()(p1==p2&&(p2=(p1=buf)+fread(buf,1,1<<20,stdin),p1==p2)?EOF:*p1++)
char buf[1<<20],*p1=buf,*p2=buf;
inline void read(int &r){
r=0;bool w=0;char ch=getchar();
while(ch<'0'||ch>'9')w=ch=='-'?1:0,ch=getchar();
while(ch>='0'&&ch<='9')r=r*10+(ch^48),ch=getchar();
r=w?-r:r;
}
int N, Q;
int a[51000];
namespace BL{
int lbuc[51000], rbuc[51000];
int sum[51000];
void Init(void){
memset(sum, 0, sizeof(sum));
for(int i = 1; i <= N; ++i)sum[i] = sum[i - 1] + a[i];
for(int i = 1; i <= N; ++i){
for(int j = i; j <= N; ++j){
int val = sum[j] - sum[i - 1];
lbuc[val] = i, rbuc[val] = j;
}
}
}
void Make(void){
for(int i = 1; i <= Q; ++i){
int q;
read(q);
// scanf("%d", &q);
printf("%d %d\n", lbuc[q] ? lbuc[q] : -1, rbuc[q] ? rbuc[q] : -1);
}
}
}
int main(){
freopen("T2.in", "r", stdin);
freopen("T2.out", "w", stdout);
read(N), read(Q);
// scanf("%d%d", &N, &Q);
for(int i = 1; i <= N; ++i)read(a[i]), --a[i];
if(N <= 20000){BL::Init(); BL::Make(); return 0;}
fprintf(stderr, "Time: %.6lf\n", (double)clock() / CLOCKS_PER_SEC);
return 0;
}
T3
很乱搞的一个暴力，我以为能过不少点，结果全被卡掉了，拿了暴力分跑路。
Code
#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
#include <unordered_map>
#define PI M_PI
#define E M_E
#define npt nullptr
#define SON i->to
#define MOD (1000000007ll)
/******************************
abbr
******************************/
using namespace std;
mt19937 rnd(random_device{}());
int rndd(int l, int r){return rnd() % (r - l + 1) + l;}
typedef unsigned int uint;
typedef unsigned long long unll;
typedef long long ll;
template<typename T = ll>
inline T read(void);
map < pair < int, int >, ll > add;
int N, M;
ll a[210000];
ll sum[210000];
int main(){
freopen("T3.in", "r", stdin);
freopen("T3.out", "w", stdout);
N = read(), M = read();
for(int i = 1; i <= N; ++i)a[i] = read() % MOD, sum[i] = (sum[i - 1] + a[i]) % MOD;
while(M--){
int opt = read();
if(opt == 1){
int x = read(), y = read(), val = read() % MOD;
auto tmp = add.find(make_pair(x, y));
if(tmp == add.end())add.insert(make_pair(make_pair(x, y), val));
else tmp->second = (tmp->second + val) % MOD;
}else{
int l = read(), r = read();
ll ans = (sum[r] - sum[l - 1] + MOD) % MOD;
for(auto i : add){
int tl = l - i.first.second, tr = r - i.first.second;
if(tr < 0)continue;
int by = max(tl / i.first.first, 0);
tl -= by * i.first.first;
tr -= by * i.first.first;
if(tl <= 0)ans = (ans + i.second) % MOD;
ans = (ans + int(tr / i.first.first) * i.second % MOD) % MOD;
}
printf("%lld\n", ans % MOD);
}
}
fprintf(stderr, "Time: %.6lf\n", (double)clock() / CLOCKS_PER_SEC);
return 0;
}
template<typename T>
inline T read(void){
T ret(0);
short flag(1);
char c = getchar();
while(c != '-' && !isdigit(c))c = getchar();
if(c == '-')flag = -1, c = getchar();
while(isdigit(c)){
ret *= 10;
ret += int(c - '0');
c = getchar();
}
ret *= flag;
return ret;
}
T4
暴力跑路。
Code
#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
#define PI M_PI
#define E M_E
#define npt nullptr
#define SON i->to
/******************************
abbr
******************************/
using namespace std;
mt19937 rnd(random_device{}());
int rndd(int l, int r){return rnd() % (r - l + 1) + l;}
typedef unsigned int uint;
typedef unsigned long long unll;
typedef long long ll;
template<typename T = int>
inline T read(void);
int N;
//x < y => -1, x > y => 1
vector < tuple < int, int, int > > relations;
int ans(0);
int a[110];
int main(){
freopen("T4.in", "r", stdin);
freopen("T4.out", "w", stdout);
N = read();
for(int i = 1; i <= N - 1; ++i){
int x = read(), y = read(), op = read();
relations.push_back(make_tuple(x, y, op));
}
int frac(1);
for(int i = 1; i <= N; ++i)frac *= i, a[i] = i;
--frac;
for(int i = 1; i <= frac; ++i){
bool flag(true);
for(auto j : relations){
int x, y, op; tie(x, y, op) = j;
if((op && a[x] <= a[y]) || (!op && a[x] >= a[y])){
flag = false;
break;
}
}
if(flag)++ans;
next_permutation(a + 1, a + N + 1);
}
printf("%d\n", ans);
fprintf(stderr, "Time: %.6lf\n", (double)clock() / CLOCKS_PER_SEC);
return 0;
}
template<typename T>
inline T read(void){
T ret(0);
short flag(1);
char c = getchar();
while(c != '-' && !isdigit(c))c = getchar();
if(c == '-')flag = -1, c = getchar();
while(isdigit(c)){
ret *= 10;
ret += int(c - '0');
c = getchar();
}
ret *= flag;
return ret;
}
是的四道乱搞且挂分，好像是 T3 还是哪道来着想了半天感觉很接近正解，不过依然寄
正解
T1
咕咕咕
UPD
update-2022_09_16 初稿
