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QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#281191 | #5464. Dice Game | Forever_Young | WA | 2ms | 3952kb | C++14 | 2.3kb | 2023-12-09 23:00:28 | 2023-12-09 23:00:28 |
Judging History
answer
#include <bits/stdc++.h>
using namespace std;
const int MOD = 998244353;
using LL = long long;
int n;
// [0, x)
int calc(int x, int w) {
int v1 = 1 << w;
int rep = v1 * 2;
int ret = x / rep * v1;
int rem = x % rep;
if (rem > v1) {
ret += rem - v1;
}
return ret;
}
int calc2(int x) {
int ret = 0;
//printf("x = %d, n = %d\n",x,n);
for (int w = 0; w < 30; w++) {
int v1_1 = calc(x + 1, w);
int v1_0 = x + 1 - v1_1;
int v2_1 = calc(n, w);
int v2_0 = n - v2_1;
//printf("%d %d %d %d\n",v1_1,v1_0,v2_1,v2_0);
ret = (ret + (1LL * v1_1 * v2_0 + 1LL * v1_0 * v2_1) % MOD * (1LL << w) % MOD) % MOD;
}
return ret;
}
// a \in [l, r], b \in [0, n), \sum(a ^ b)
int getsum(int l, int r) {
return (calc2(r) - calc2(l - 1) + MOD) % MOD;
}
int quick_pow(int a, int x) {
int ret = 1;
while(x) {
if (x & 1) {
ret = 1LL * ret * a % MOD;
}
a = 1LL * a * a % MOD;
x >>= 1;
}
return ret;
}
int seqsum(int l, int r) {
return 1LL * (r + l) * (r - l + 1) / 2 % MOD;
}
int main() {
int T;
scanf("%d",&T);
while(T--) {
scanf("%d",&n);
int ans = calc2(0);
for (int w = 0; w < 30; w++) {
// hight bit = 2^w
if ((1 << w) >= n) {
break;
}
int L = (1 << w) - 1, R = (1 << (w + 1));
if ((1 << (w + 1)) >= n) {
R = n;
}
// need to xor
auto check = [&](int x) {
LL v1 = 1LL * x * n;
LL v2 = getsum(x, x);
return v2 >= v1;
};
while(L < R - 1) {
int mid = (L + R) >> 1;
if (check(mid)) {
L = mid;
} else {
R = mid;
}
}
// printf("w = %d, L = %d, R = %d\n", w, L, R);
ans = (ans + 1LL * seqsum(R, min((1 << (w + 1)) - 1, n - 1)) * n) % MOD;
ans = (ans + getsum(1 << w, L)) % MOD;
// printf("ans = %d\n", ans);
}
ans = 1LL * ans * quick_pow(n, MOD - 2) % MOD;
ans = 1LL * ans * quick_pow(n, MOD - 2) % MOD;
printf("%d\n", ans);
}
}
Details
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Test #1:
score: 100
Accepted
time: 0ms
memory: 3952kb
input:
4 1 2 3 4
output:
0 249561089 776412276 2
result:
ok 4 number(s): "0 249561089 776412276 2"
Test #2:
score: -100
Wrong Answer
time: 2ms
memory: 3848kb
input:
100 119 75 29 10 17 29 449 71 72 12 79 117 83 80 35 272 105 497 346 287 362 140 297 167 111 419 210 212 170 413 373 210 196 39 1 101 258 496 333 293 392 2 187 431 157 342 436 106 449 136 378 243 357 325 237 254 22 292 62 435 18 446 471 18 42 377 181 350 19 389 212 58 45 70 52 63 107 71 66 355 381 30...
output:
645006489 296012775 400009943 299473312 221064504 400009943 60548260 896063466 573066250 471393174 723451295 531171954 143020402 389315350 560646647 43176836 269095960 284396636 191400715 269215551 967774080 745220060 584864173 5941827 724073586 701650152 262576881 417830609 833275086 916357319 1435...
result:
wrong answer 11th numbers differ - expected: '175624519', found: '723451295'