31 lines
551 B
C++
31 lines
551 B
C++
#include <bits/stdc++.h>
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using namespace std;
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//P1047 校门外的树
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int main() {
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int L, M;
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cin >> L >> M;
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int array[L];
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for (int i = 0; i <= L; i++) {
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array[i] = 0;
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}
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for (int i = 1; i <= M; i++) {
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int s, t;
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cin >> s >> t;
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for (int j = s; j <= t; j++) {
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array[j] = 1;
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}
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}
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int count = 0;
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for (int i = 0; i <= L; i++) {
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if (array[i] == 0) {
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count++;
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}
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}
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cout << count << endl;
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return 0;
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} |