- CodeForces
- 2020-10-04 22:20:52 @
RT
9 条评论
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Dry_ice LV 7 MOD @ 2020-10-11 18:13:34
@IcproX: 快来!
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2020-10-05 20:48:36@
@Dry_ice 在吗?
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2020-10-05 01:43:24@
#include<stdio.h> #include<string.h> #include<iostream> #define LL long long const int N = 1e5; using namespace std; LL mod = 1e9 + 7; char a[N + 5]; LL ans = 0, p[N + 5], s[N + 5]; int main() { scanf("%s", a + 1); int l = strlen(a + 1); p[1] = 1; for(int i = 2; i <= l; ++i) p[i] = (p[i - 1] * 10) % mod; for(int i = 1; i <= l; ++i) s[i] = (s[i - 1] + i * p[i] % mod) % mod; ans = (l - 1) * l / 2 % mod * (a[l] - '0') % mod; // cout << ans << endl;/ for(int i = l - 1; i >= 1; --i) { int t = a[i] - '0'; ans = (ans + (i - 1) * i / 2 * t * p[l - i + 1] % mod) % mod; ans = (ans + s[l - i] * t % mod) % mod; // cout << ans << endl; } cout << ans << endl; return 0; }
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2020-10-05 01:43:07@
怎么也没过, WA on#6
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2020-10-05 01:42:52@
终于C
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2020-10-05 00:24:25@
再见,一题没过
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2020-10-04 23:53:50@
有人么?
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2020-10-04 23:50:06@
不应该是10.5比赛吗?0:05开始/xyx
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2020-10-04 23:49:35@
我来了
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