难度:4
- 描述
- You want to processe a sequence of n distinct integers by swapping two adjacent sequence elements until the sequence is sorted in ascending order. Then how many times it need.
For example, 1 2 3 5 4, we only need one operation : swap 5 and 4.- 输入
- The input consists of T number of test cases.(<0T<1000) Each case consists of two lines: the first line contains a positive integer n (n <= 1000); the next line contains a permutation of the n integers from 1 to n.
- 输出
- For each case, output the minimum times need to sort it in ascending order on a single line.
- 样例输入
-
2 3 1 2 3 4 4 3 2 1
- 样例输出
-
0 6
#include<stdio.h> #include<string.h> int num[1004],n; int lowbit(int x) { return x&(-x); } void add(int x) //更新含有x的数组个数 { while(x<=n) { num[x]++; x+=lowbit(x); } } int sum(int x) //向下统计小于x的个数 { int total=0; while(x>0) { total+=num[x]; x-=lowbit(x); } return total; } int main() { int x,cases; scanf("%d",&cases); while(cases--) { scanf( "%d",&n); memset( num,0,sizeof( num )); int ss = 0; for( int i = 0; i < n; ++i ) { scanf( "%d",&x); add(x); ss += (i-sum( x - 1 )); } printf( "%d\n",ss ); } return 0; }