39 lines
622 B
C++
39 lines
622 B
C++
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#include <queue>
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#include <cstdio>
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typedef struct TreeNode {
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struct TreeNode *l;
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struct TreeNode *r;
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int val;
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} TreeNode;
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// answer begins here
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void BFS(TreeNode *node) {
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std::queue<TreeNode *> todo;
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if (node) {
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todo.push(node);
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}
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while (!todo.empty()) {
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for (int i = 0, size = todo.size(); i < size; i++) {
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auto ptr = todo.front();
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std::printf("%d ", ptr->val);
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todo.pop();
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if (ptr->l) {
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todo.push(ptr->l);
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}
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if (ptr->r) {
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todo.push(ptr->r);
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}
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}
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printf("\n");
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}
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}
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// answer ends
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int main(void) {
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BFS(nullptr);
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return 0;
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}
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