34 lines
731 B
C++
34 lines
731 B
C++
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#include <bits/stdc++.h>
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// https://www.acwing.com/solution/content/34401/
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using namespace std;
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const int N = 20;
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int a[N];
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bool st[N];
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int n = 3;
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void dfs(int step) {
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if (step == n + 1) {
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for (int i = 1; i <= n; i++)printf("%d ", a[i]);
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printf("\n");
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return;
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}
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for (int i = 1; i <= n; i++) {
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if (!st[i]) {
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//记录本位置放了哪个数字
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a[step] = i;
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//标识此数字已使用过了
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st[i] = true;
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//走到下一个位置
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dfs(step + 1);
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//反向标识此数字没有使用过
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st[i] = false;
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}
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}
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}
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int main() {
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dfs(1);
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return 0;
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}
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