标签:
Description
Edward has an array A with N integers. He defines the beauty of an array as the summation of all distinct integers in the array. Now Edward wants to know the summation of the beauty of all contiguous subarray of the array A.
Input
There are multiple test cases. The first line of input contains an integer T indicating the number of test cases. For each test case:
The first line contains an integer N (1 <= N <= 100000), which indicates the size of the array. The next line contains N positive integers separated by spaces. Every integer is no larger than 1000000.
Output
For each case, print the answer in one line.
Sample Input
3 5 1 2 3 4 5 3 2 3 3 4 2 3 3 2
Sample Output
105 21 38
题目描述: 求一段序列中连续子序列的和,如果这段连续子序列中有重复的话,(the summation of all distinct integers in the arra),这个序列中不相同的数的和,也就是说只计算一次。
如果要求的是一段序列中连续子序列的个数,那么如果定义d[i]为以i结尾的连续子序列的个数,d[i]=d[i-1]+1;
我们定义d[i]为以i结尾的连续子序列的和,那么如果不重复d[i]=d[i-1]+a*i;
,如果重复的话,假设1 2 3 4 5 6 7。。。。。i,如果在第j位,那么(i i-1),(i,i-2),(i,i-3)。。。。(i,j+1)这些连续子序列的值可以加上a的值;
(i,j),(i,j-1),(i,j-2),(i,1),这些值都会包含重复的i,j位置上的值,因为只需要算一次,所以不需要给这些以i
结尾的子序列加上a,这些子序列的个数,总共有j个,所以我们只需要用一个数组A标记上A[a]=i;那么d[i]=d[i-1]+a+(i-1-A[a])*a;
如果a之前没有出现过,那么A[a]等于0;如果a之前出现过,减去包含重复值的子序列的个数,也就是A[a]。
#include <iostream> #include <cstdio> #include <string.h> #include <queue> #include <set> #include <algorithm> #define LL long long #define M 100100 using namespace std; LL dp[M]; LL visit[M]; void init() { memset(dp,0,sizeof(dp)); memset(visit,0,sizeof(visit)); } void solve() { int n; LL data; scanf("%d",&n); for(int i=1;i<=n;i++) { scanf("%lld",&data); dp[i]=dp[i-1] + data +(i-1-visit[data]) * data; visit[data]=i; } LL answer=0; for(int i=1;i<=n;i++) answer+=dp[i]; printf("%lld\n",answer); } int main() { int T; scanf("%d",&T); while(T--) { init(); solve(); } // system("pause"); return 0; }
标签:
原文地址:http://www.cnblogs.com/xianbin7/p/4473439.html