25 lines
636 B
C++
25 lines
636 B
C++
#include <bits/stdc++.h>
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using namespace std;
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const int N = 1e5 + 10;
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int n;
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int w[N];
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int f[N][3];
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int main() {
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scanf("%d", &n);
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for (int i = 1; i <= n; i++) scanf("%d", &w[i]);
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//无法判定或肯定不合理的
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memset(f, -0x3f, sizeof f);
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//这些状态是合理的
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for (int i = 0; i <= n; i++) f[i][0] = 0;
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//开始进行状态转移
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for (int i = 1; i <= n; ++i) {
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f[i][0] = max(f[i - 1][0], f[i - 1][2]);
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f[i][1] = max(f[i - 1][1], f[i - 1][0] - w[i]);
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f[i][2] = f[i - 1][1] + w[i];
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}
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printf("%d\n", max(f[n][0], f[n][2]));
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return 0;
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}
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