Merge Sets

AtCoder
IDabc306_f
Time4000ms
Memory256MB
Difficulty
For two sets of integers, $A$ and $B$, such that $A \cap B = \emptyset$, we define $f(A,B)$ as follows. * Let $C=(C_1,C_2,\dots,C_{|A|+|B|})$ be a sequence consisting of the elements of $A \cup B$, sorted in ascending order. * Take $k_1,k_2,\dots,k_{|A|}$ such that $A=\lbrace C_{k_1},C_{k_2},\dots,C_{k_{|A|}}\rbrace$. Then, let $\displaystyle f(A,B)=\sum_{i=1}^{|A|} k_i$. For example, if $A=\lbrace 1,3\rbrace$ and $B=\lbrace 2,8\rbrace$, then $C=(1,2,3,8)$, so $A=\lbrace C_1,C_3\rbrace$; thus, $f(A,B)=1+3=4$. We have $N$ sets of integers, $S_1,S_2\dots,S_N$, each of which has $M$ elements. For each $i\ (1 \leq i \leq N)$, $S_i = \lbrace A_{i,1},A_{i,2},\dots,A_{i,M}\rbrace$. Here, it is guaranteed that $S_i \cap S_j = \emptyset\ (i \neq j)$. Find $\displaystyle \sum_{1\leq i<j \leq N} f(S_i, S_j)$. ## Constraints * $1\leq N \leq 10^4$ * $1\leq M \leq 10^2$ * $1\leq A_{i,j} \leq 10^9$ * If $i_1 \neq i_2$ or $j_1 \neq j_2$, then $A_{i_1,j_1} \neq A_{i_2,j_2}$. * All input values are integers. ## Input The input is given from Standard Input in the following format: $N$ $M$ $A_{1,1}$ $A_{1,2}$ $\dots$ $A_{1,M}$ $\vdots$ $A_{N,1}$ $A_{N,2}$ $\dots$ $A_{N,M}$ [samples]
Samples
Input #1
3 2
1 3
2 8
4 6
Output #1
12

$S_1$ and $S_2$ respectively coincide with $A$ and $B$ exemplified in the problem statement, and $f(S_1,S_2)=1+3=4$. Since $f(S_1,S_3)=1+2=3$ and $f(S_2,S_3)=1+4=5$, the answer is $4+3+5=12$.
Input #2
1 1
306
Output #2
0
Input #3
4 4
155374934 164163676 576823355 954291757
797829355 404011431 353195922 138996221
191890310 782177068 818008580 384836991
160449218 545531545 840594328 501899080
Output #3
102
API Response (JSON)
{
  "problem": {
    "name": "Merge Sets",
    "description": {
      "content": "For two sets of integers, $A$ and $B$, such that $A \\cap B = \\emptyset$, we define $f(A,B)$ as follows. *   Let $C=(C_1,C_2,\\dots,C_{|A|+|B|})$ be a sequence consisting of the elements of $A \\cup B$,",
      "description_type": "Markdown"
    },
    "platform": "AtCoder",
    "limit": {
      "time_limit": 4000,
      "memory_limit": 262144
    },
    "difficulty": "None",
    "is_remote": true,
    "is_sync": true,
    "sync_url": null,
    "sign": "abc306_f"
  },
  "statements": [
    {
      "statement_type": "Markdown",
      "content": "For two sets of integers, $A$ and $B$, such that $A \\cap B = \\emptyset$, we define $f(A,B)$ as follows.\n\n*   Let $C=(C_1,C_2,\\dots,C_{|A|+|B|})$ be a sequence consisting of the elements of $A \\cup B$,...",
      "is_translate": false,
      "language": "English"
    }
  ]
}
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