Given an array containing a permutation of 1 to n, you have to find the minimum number of swaps to sort the array in ascending order. A swap means, you can exchange any two elements of the array.
For example, let n = 4, and the array be 4 2 3 1, then you can sort it in ascending order in just 1 swaps (by swapping 4 and 1).
Input
Input starts with an integer T (≤ 100), denoting the number of test cases.
Each case contains two lines, the first line contains an integer n (1 ≤ n ≤ 100). The next line contains n integers separated by spaces. You may assume that the array will always contain a permutation of 1 to n.
Output
For each case, print the case number and the minimum number of swaps required to sort the array in ascending order.
Sample Input
Sample Input |
Output for Sample Input |
3 4 4 2 3 1 4 4 3 2 1 4 1 2 3 4 |
Case 1: 1 Case 2: 2 Case 3: 0 |
#include<bits/stdc++.h> using namespace std; typedef long long LL; const int maxn = 100+10; int num[maxn]; bool vis[maxn]; int n; #define REP(_,a,b) for(int _ = (a); _ <= (b); _++) int main(){ int ncase,T = 1; cin >> ncase; while(ncase--) { scanf("%d",&n); memset(vis,0,sizeof vis); int ans = 0; for(int i = 1; i <= n; i++) scanf("%d",&num[i]); for(int i = 1; i <= n; i++) { if(i==num[i]) continue; int idx; for(int j = i+1; j <= n; j++) { if(num[j]==i) { idx = j; break; } } num[idx] = num[i]; ans++; } printf("Case %d: %d\n",T++,ans); } return 0; }