2019牛客多校8_B题算法日常[7/100]
164 words
One minute
题目
题目链接以及描述
2019牛客多校8_B题
![https://cdn.jsdelivr.net/gh/wolfdan666/BlogPic/%E7%AE%97%E6%B3%95/2019%E5%B9%B4%E5%A4%9A%E6%A0%A1/%E7%89%9B%E5%AE%A2/%E7%AC%AC%E5%85%AB%E5%9C%BA/B1.png https://cdn.jsdelivr.net/gh/wolfdan666/BlogPic/%E7%AE%97%E6%B3%95/2019%E5%B9%B4%E5%A4%9A%E6%A0%A1/%E7%89%9B%E5%AE%A2/%E7%AC%AC%E5%85%AB%E5%9C%BA/B1.png](/svg/loading.min.svg)
题意以及思路
![https://cdn.jsdelivr.net/gh/wolfdan666/BlogPic/%E7%AE%97%E6%B3%95/2019%E5%B9%B4%E5%A4%9A%E6%A0%A1/%E7%89%9B%E5%AE%A2/%E7%AC%AC%E5%85%AB%E5%9C%BA/B2.png https://cdn.jsdelivr.net/gh/wolfdan666/BlogPic/%E7%AE%97%E6%B3%95/2019%E5%B9%B4%E5%A4%9A%E6%A0%A1/%E7%89%9B%E5%AE%A2/%E7%AC%AC%E5%85%AB%E5%9C%BA/B2.png](/svg/loading.min.svg)
AC代码
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#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int maxn = 100000 + 5;
int a[maxn], b[maxn], c[maxn];
int main() {
int n;
scanf("%d", &n);
for(int i = 1; i <= n; i++) {
scanf("%d", &a[i]);
/*c[i]记录的是a[i]的上一个位置加1的位置*/
c[i] = b[a[i]]+1;
b[a[i]] = i;
}
ll ans = 0;
for(int i = 1; i <= n; i++) {
ans += 1LL*(n-i+1)*(i-c[i]+1);
}
printf("%lld\n", ans);
return 0;
}
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每日一句叨叨
但求精进,无问西东