存在
模拟赛的时候像了一些奇奇怪怪的做法,大概就是想到打表,但是 ##### 压成 5#,最终展开即可,这样最终打出来了约
x123
4567891011
12using namespace std;13
14mt19937 rnd(random_device{}());15int rndd(int l, int r){return rnd() % (r - l + 1) + l;}16bool rnddd(int x){return rndd(1, 100) <= x;}17
18typedef unsigned int uint;19typedef unsigned long long unll;20typedef long long ll;21typedef long double ld;22
23
24
25template < typename T = int >26inline T read(void);27
28ll F(ll x){29 if(x == 1)return 1;30 ll ret(0);31 for(ll i = 1; i * i <= x; ++i)32 if(!(x % i) && __gcd(i, x / i) == 1)ret += i + x / i;33 return ret;34 // printf("f(%lld) = %lld%s", x, ret, x % 10 == 0 ? "\n" : "; ");35}36map < ll, ll > cnt;37map < char, int > mp;38map < int, char > rmp;39map < ll, ll > unex;40
41int main(){42 freopen("out.txt", "w", stdout);43 fprintf(stderr, "Begin to build map...\n");44 mp['#'] = 0, rmp[0] = '#';45 printf("mp['#']=0;");46 for(int i = 1; i <= 26; ++i){47 mp['a' + i - 1] = i, rmp[i] = 'a' + i - 1,48 printf("mp['%c']=%d;", char('a' + i - 1), i);49 }printf("\n");50 for(int i = 1; i <= 26; ++i){51 mp['A' + i - 1] = i + 26, rmp[i + 26] = 'A' + i - 1,52 printf("mp['%c']=%d;", char('A' + i - 1), i + 26);53 }printf("\n\n\n");54 fprintf(stderr, "Begin to cal f(x)...\n");55 for(int i = 1; i <= 11000000; ++i)cnt[F(i)]++;56 fprintf(stderr, "Complete.\n");57 // printf("string ans = \"#");58 string ans; ans += '#';59 for(int i = 1; i <= 100000; ++i){60 if(rmp.find(cnt[i]) == rmp.end())unex[i] = cnt[i], ans += '*';//printf("#");61 else ans += rmp[cnt[i]];//printf("%c", rmp[cnt[i]]);62 }63 // printf("\";\n\n");64 {65 printf("string ans = \"");66 char lst('@'); int cnt(0);67 for(auto it = ans.begin(); it != ans.end(); ++it){68 if(lst == '@' || *it == lst){69 if(cnt == 9)printf("%d%c", cnt, lst), cnt = 0;70 lst = *it, ++cnt;71 }else{72 if(cnt == 1)printf("%c", lst);73 else printf("%d%c", cnt, lst);74 lst = *it, cnt = 1;75 }76 }if(cnt != 1)printf("%d%c", cnt, lst);77 else printf("%c", lst);78 printf("\";\n\n");79 }80 //begin at 994000081 string bans;82 // printf("string bans = \"");83 for(int i = 9940000; i <= 10000000; ++i){84 if(rmp.find(cnt[i]) == rmp.end())unex[i] = cnt[i], bans += '*';85 // fprintf(stderr, "Find unexist ans ans[%d] = %lld\n", i, cnt[i]), bans += '*';//, printf("#");86 else bans += rmp[cnt[i]];//printf("%c", rmp[cnt[i]]);87 }88
89 {90 printf("string bans = \"");91 char lst('@'); int cnt(0);92 for(auto it = bans.begin(); it != bans.end(); ++it){93 if(lst == '@' || *it == lst){94 if(cnt == 9)printf("%d%c", cnt, lst), cnt = 0;95 lst = *it, ++cnt;96 }else{97 if(cnt == 1)printf("%c", lst);98 else printf("%d%c", cnt, lst);99 lst = *it, cnt = 1;100 }101 }if(cnt != 1)printf("%d%c", cnt, lst);102 else printf("%c", lst);103 printf("\";\n\n");104 }105 // }printf("\";\n\n");106
107 // for(auto mp : cnt){printf("Ans[ %lld ] = %lld\n", mp.first, mp.second);}108
109 for(auto mp : unex){110 printf("u[%lld]=%lld;", mp.first, mp.second);111 }printf("\n\n");112
113 fprintf(stderr, "Time: %.6lf\n", (double)clock() / CLOCKS_PER_SEC);114 return 0;115}116
117template < typename T >118inline T read(void){119 T ret(0);120 int flag(1);121 char c = getchar();122 while(c != '-' && !isdigit(c))c = getchar();123 if(c == '-')flag = -1, c = getchar();124 while(isdigit(c)){125 ret *= 10;126 ret += int(c - '0');127 c = getchar();128 }129 ret *= flag;130 return ret;131}xxxxxxxxxx95123
4567891011
12using namespace std;13
14mt19937 rnd(random_device{}());15int rndd(int l, int r){return rnd() % (r - l + 1) + l;}16bool rnddd(int x){return rndd(1, 100) <= x;}17
18typedef unsigned int uint;19typedef unsigned long long unll;20typedef long long ll;21typedef long double ld;22
23
24
25template < typename T = int >26inline T read(void);27
28map < char, int > mp;29map < int, int > u;30
31
32string ans = "#a#4a#3a#b#a2#ab#b3#c.....#b9#2#a5#c#a#a#a3#k";33
34string bans = "I#a#a3#a7#a3#c7#a3#j3#a3#c3#b5#a9#a7#a9#2#l5#a5#a#a#e3......#g9#a#a#a#a3#a9#a#b3#a3#v";35
36//篇幅过长省略37
38string rans, rbans;39int main(){40 freopen("number.in", "r", stdin);41 freopen("number.out", "w", stdout);42
43
44 mp['#']=0;mp['a']=1;mp['b']=2;mp['c']=3;mp['d']=4;mp['e']=5;mp['f']=6;mp['g']=7;mp['h']=8;mp['i']=9;mp['j']=10;mp['k']=11;mp['l']=12;mp['m']=13;mp['n']=14;mp['o']=15;mp['p']=16;mp['q']=17;mp['r']=18;mp['s']=19;mp['t']=20;mp['u']=21;mp['v']=22;mp['w']=23;mp['x']=24;mp['y']=25;mp['z']=26;45 mp['A']=27;mp['B']=28;mp['C']=29;mp['D']=30;mp['E']=31;mp['F']=32;mp['G']=33;mp['H']=34;mp['I']=35;mp['J']=36;mp['K']=37;mp['L']=38;mp['M']=39;mp['N']=40;mp['O']=41;mp['P']=42;mp['Q']=43;mp['R']=44;mp['S']=45;mp['T']=46;mp['U']=47;mp['V']=48;mp['W']=49;mp['X']=50;mp['Y']=51;mp['Z']=52;46
47 u[8640]=63;u[10080]=65;u[11520]=60;u[12096]=54;u[12960]=71;u[14400]=69;u[15120]=69;u[17280]=88;u[18144]=57;u[20160]=89;u[21600]=81;u[23040]=67;u[23760]=56;u[24192]=67;u[24480]=59;u[25200]=78;u[25920]=102;u[26880]=53;u[27360]=56;u[28800]=81;u[30240]=121;u[31680]=73;u[32256]=53;u[32400]=78;u[33600]=65;u[34560]=118;u[35280]=60;u[36000]=68;u[36288]=84;u[36720]=55;u[37440]=62;u[37800]=58;u[38880]=87;u[40320]=122;u[41040]=63;u[41472]=56;u[42336]=66;u[43200]=131;u[44352]=55;u[45360]=104;u[46080]=87;u[47520]=96;u[48384]=94;u[48960]=78;u[50400]=109;u[51840]=144;u[52416]=56;u[53760]=66;u[54000]=71;u[54432]=72;u[54720]=88;u[55440]=78;u[56160]=85;u[56448]=59;u[57024]=61;u[57456]=56;u[57600]=116;u[58320]=54;u[58752]=54;u[60480]=188;u[61200]=69;u[62208]=66;u[63360]=100;u[63504]=58;u[64512]=66;u[64800]=126;u[65280]=63;u[65520]=68;u[65664]=71;u[66528]=74;u[67200]=83;u[68040]=56;u[68400]=57;u[68544]=57;u[69120]=149;u[70560]=101;u[71280]=81;u[72000]=94;u[72576]=116;u[72960]=55;u[73440]=95;u[73920]=72;u[74880]=90;u[75600]=136;u[76032]=69;u[76608]=71;u[76800]=58;u[77760]=143;u[78624]=71;u[79200]=90;u[80640]=160;u[81600]=62;u[82080]=100;u[82944]=79;u[83160]=59;u[84000]=73;u[84240]=72;u[84672]=91;u[85536]=57;u[85680]=74;u[86400]=179;u[87360]=74;u[87552]=55;u[88128]=56;u[88704]=75;u[89280]=62;u[89856]=57;u[90000]=55;u[90720]=190;u[91200]=59;u[92160]=100;u[92400]=60;u[93312]=58;u[93600]=85;u[94080]=70;u[95040]=143;u[95760]=83;u[96000]=56;u[96768]=115;u[97200]=96;u[97920]=119;u[98280]=60;u[98496]=78;u[99360]=56;u[99792]=67;u[99840]=56;u[9940320]=193;u[9940800]=78;u[9941760]=59;u[9942912]=160;u[9943560]=87;u[9944064]=69;u[9945000]=100;u[9945600]=300;u[9945936]=90;u[9946800]=92;u[9947040]=57;u[9947448]=54;u[9947520]=196;u[9948400]=57;u[9948672]=55;u[9948960]=309;u[9950400]=96;u[9950976]=69;u[9951120]=88;u[9952200]=64;u[9952800]=125;u[9953280]=1110;u[9953568]=61;u[9954000]=115;u[9955200]=200;u[9956520]=75;u[9956736]=54;u[9957600]=90;u[9958080]=56;u[9958464]=72;u[9959040]=816;u[9959760]=123;u[9960000]=97;u[9960192]=125;u[9960720]=77;u[9961056]=155;u[9961920]=84;u[9962400]=63;u[9962496]=81;u[9963000]=97;u[9963360]=229;u[9963648]=83;u[9964800]=190;u[9966240]=64;u[9966528]=99;u[9966600]=53;u[9967104]=200;u[9968112]=74;u[9968400]=122;u[9968640]=69;u[9969120]=153;u[9969480]=60;u[9969600]=59;u[9970128]=91;u[9970560]=134;u[9971520]=116;u[9972480]=185;u[9972720]=130;u[9973152]=116;u[9974016]=262;u[9975168]=59;u[9975600]=79;u[9976320]=67;u[9977760]=146;u[9979200]=1789;u[9980928]=252;u[9982440]=62;u[9983232]=69;u[9983520]=65;u[9984000]=321;u[9984240]=55;u[9984384]=122;u[9984480]=56;u[9984576]=72;u[9984600]=66;u[9985248]=136;u[9985680]=80;u[9985920]=61;u[9986400]=93;u[9987120]=86;u[9987600]=102;u[9987840]=606;u[9989280]=80;u[9989568]=72;u[9989760]=84;u[9990000]=179;u[9990288]=87;u[9991296]=140;u[9991800]=79;u[9991872]=60;u[9992160]=113;u[9993600]=103;u[9993984]=149;u[9994320]=82;u[9994752]=67;u[9995328]=59;u[9995520]=91;u[9996000]=232;u[9996480]=130;u[9997344]=228;u[9998208]=90;u[9998640]=57;u[9999360]=652;48
49
50
51
52 for(auto it = ans.begin(); it != ans.end(); ++it){53 if(!isdigit(*it))rans += *it;54 else{55 int cnt = *it - '0';56 advance(it, 1);57 for(int i = 1; i <= cnt; ++i)rans += *it;58 }59 }60 for(auto it = bans.begin(); it != bans.end(); ++it){61 if(!isdigit(*it))rbans += *it;62 else{63 int cnt = *it - '0';64 advance(it, 1);65 for(int i = 1; i <= cnt; ++i)rbans += *it;66 }67 }68 // cout << rans;69 ll N = read < ll >();70 if((100000ll < N && N < 9940000ll) || N > 10000000ll)printf("%d\n", rnddd(50) ? 1 : 0), exit(0);71 if(u.find((int)N) != u.end())printf("%d\n", u[(int)N]);72 else{73 if(N <= 100000)printf("%d\n", mp[rans.at(N)]);74 else printf("%d\n", mp[rbans.at(N - 9940000)]);75 }76 fprintf(stderr, "Time: %.6lf\n", (double)clock() / CLOCKS_PER_SEC);77 return 0;78}79
80template < typename T >81inline T read(void){82 T ret(0);83 int flag(1);84 char c = getchar();85 while(c != '-' && !isdigit(c))c = getchar();86 if(c == '-')flag = -1, c = getchar();87 while(isdigit(c)){88 ret *= 10;89 ret += int(c - '0');90 c = getchar();91 }92 ret *= flag;93 return ret;94}95
给定
赛时没啥思路,拿了
xxxxxxxxxx83123
4567891011
12using namespace std;13
14mt19937 rnd(random_device{}());15int rndd(int l, int r){return rnd() % (r - l + 1) + l;}16bool rnddd(int x){return rndd(1, 100) <= x;}17
18typedef unsigned int uint;19typedef unsigned long long unll;20typedef long long ll;21typedef long double ld;22
2324
25template < typename T = int >26inline T read(void);27
28int N, M;29ll ans(0);30basic_string < int > arr;31basic_string < int > sub;32set < basic_string < int > > exist;33
34void dfs_sub(int dep = 1){35 if(dep > N){36 if(exist.find(sub) == exist.end())++ans, exist.insert(sub);37 return;38 }39 sub += arr.at(dep - 1);40 dfs_sub(dep + 1);41 sub.pop_back();42 dfs_sub(dep + 1);43}44
45void Cal(void){46 exist.clear();47 dfs_sub();48 ans %= MOD;49}50
51void dfs(int dep = 1){52 if(dep > N)return Cal();53 for(int i = 1; i <= M; ++i)54 arr += i, dfs(dep + 1), arr.pop_back();55}56
57int main(){58 freopen("sequence.in", "r", stdin);59 freopen("sequence.out", "w", stdout);60 N = read(), M = read();61 if((ll)N * M > (ll)1e6)exit(1);62 if(M == 1)printf("%d\n", N + 1), exit(0);63 dfs();64 printf("%lld\n", ans);65 fprintf(stderr, "Time: %.6lf\n", (double)clock() / CLOCKS_PER_SEC);66 return 0;67}68
69template < typename T >70inline T read(void){71 T ret(0);72 int flag(1);73 char c = getchar();74 while(c != '-' && !isdigit(c))c = getchar();75 if(c == '-')flag = -1, c = getchar();76 while(isdigit(c)){77 ret *= 10;78 ret += int(c - '0');79 c = getchar();80 }81 ret *= flag;82 return ret;83}给定树形结构,每个点代表商店,有
这题也想了挺久的,最终能想到的思路是 有依赖的多重背包,然后就不太会写了,实际上还是数据范围看的有点问题,否则这个东西直接把多重背包无脑一点做
首先
首先考虑若我们将
于是不难发现对于质数
至此不难想到,我们现在已知
考虑如何分解,显然对于 unordered_map 里,同时需要记录基于的质数,而若其存在
于是可以考虑根号枚举
此时可以通过背包处理,即 unordered_map 维护,而记录基于某个质数便是为了在转移的时候不出现同时使用多个质数的情况,所以对每个质数开个 basic_string 记录其所有合法的 unordered_map。
尝试分析复杂度,考虑 DP 时,显然枚举素数时最多有
Tips:注意计算过程中包括但不限于 Miller-Rabin 有多处会超过 long long 范围,需要开 __int128_t 或用 long double 快速乘,可以通过 Sanitizer 检测 signed-integer-overflow 并输入最大的数据进行测试寻找报错。
xxxxxxxxxx123123
4567891011
12using namespace std;13
14mt19937 rnd(random_device{}());15int rndd(int l, int r){return rnd() % (r - l + 1) + l;}16bool rnddd(int x){return rndd(1, 100) <= x;}17
18typedef unsigned int uint;19typedef unsigned long long unll;20typedef long long ll;21typedef long double ld;22
2324
25template < typename T = int >26inline T read(void);27
28ll N;29unordered_map < ll, ll > dp[2];30basic_string < ll > Prime;31unordered_map < ll, ll > pows;32bitset < LIM + 100 > notPrime;33unordered_map < ll, basic_string < ll > > tpow;34basic_string < ll > tot;35
36namespace MillerRabin{37 int radix[10] = {0, 2, 3, 5, 7, 11, 13, 19, 17};38 ll qpow(ll a, ll b, ll MOD){39 ll ret(1), mul(a);40 while(b){41 if(b & 1)ret = (__int128_t)ret * mul % MOD;42 b >>= 1;43 mul = (__int128_t)mul * mul % MOD;44 }return ret;45 }46 bool Check(ll N){47 if(N <= 2 || !(N & 1))return N == 2;48 ll base(N - 1); int cpow(0);49 while(base % 2 == 0)base >>= 1, ++cpow;50 for(int t = 1; t <= 8; ++t){51 ll cur = qpow(radix[t], base, N);52 if(cur == 1)continue;53 for(int i = 1; i <= cpow; ++i){54 if(cur == N - 1)break;55 cur = (__int128_t)cur * cur % N;56 if(i == cpow)return false;57 }58 }return true;59 }60};61
62void Sieve(void){63 for(ll i = 2; i <= LIM; ++i){64 if(!notPrime[i])Prime += i;65 for(auto p : Prime){66 if(p * i > LIM)break;67 notPrime[p * i] = true;68 if(i % p == 0)break;69 }70 }71}72void Init(void){73 Sieve();74 for(auto p : Prime){75 ll base(p);76 while(base <= N)pows[base] = p, base *= p;77 }78 for(ll i = 1; i * i <= N; ++i){79 if(N % i)continue;80 if(pows.find(i - 1) != pows.end())81 tpow[pows[i - 1]] += i, tot += pows[i - 1];82 if(i * i != N){83 if(pows.find(N / i - 1) != pows.end())84 tpow[pows[N / i - 1]] += N / i, tot += pows[(N / i) - 1];85 else if(MillerRabin::Check(N / i - 1))86 tpow[N / i - 1] += N / i, tot += N / i - 1;87 }88 }89 sort(tot.begin(), tot.end());90 tot.erase(unique(tot.begin(), tot.end()), tot.end());91}92
93int main(){94 N = read < ll >();95 Init();96 dp[0][1] = 1;97 int base(0);98 for(auto p : tot){99 base ^= 1, dp[base] = dp[base ^ 1];100 for(auto lst : dp[base ^ 1])101 for(auto pri : tpow[p])102 if((__int128_t)pri * lst.first <= N && N % (pri * lst.first) == 0)103 dp[base][pri * lst.first] += lst.second;104 }printf("%lld\n", dp[base][N]);105 fprintf(stderr, "Time: %.6lf\n", (double)clock() / CLOCKS_PER_SEC);106 return 0;107}108
109template < typename T >110inline T read(void){111 T ret(0);112 int flag(1);113 char c = getchar();114 while(c != '-' && !isdigit(c))c = getchar();115 if(c == '-')flag = -1, c = getchar();116 while(isdigit(c)){117 ret *= 10;118 ret += int(c - '0');119 c = getchar();120 }121 ret *= flag;122 return ret;123}存在一些高妙推导,可以从奇怪的组合意义或者二项式反演得到,最终可以任意模数 NTT 优化,总是很高秒就对了。
点分治 + 背包,先去复习一下点分治再来补。
update-2023_02_10 初稿