[CF846A]Curriculum Vitae题解

枚举一个点，假设它一定符合条件，据此珂以\(O(n)\)算出要删去几个点
于是就\(O(n^2)\)解决了，貌似加一个前缀和可以在\(O(n)\)的时间复杂度内解决本问题，但对于这个数据范围来说\(O(n^2)\)戳戳有余

放个代码：

#include <cstdio> 
#define ll long long

inline ll read(){
    ll x = 0; int zf = 1; char ch = ' ';
    while (ch != '-' && (ch < '0' || ch > '9')) ch = getchar();
    if (ch == '-') zf = -1, ch = getchar();
    while (ch >= '0' && ch <= '9') x = x * 10 + ch - '0', ch = getchar(); return x * zf;
}

int a[105];

int main(){
    int n = read();
    for (int i = 1; i <= n; ++i)
        a[i] = read();
    int ans = 0, cnt;
    for (int i = 1; i <= n; ++i){
        cnt = 0;
        for (int j = i + 1; j <= n; ++j)
            if (!a[j])
                ++cnt;
        for (int j = 1; j < i; ++j)
            if (a[j])
                ++cnt;
        if (n - cnt > ans)
            ans = n - cnt;
    }
    printf("%d", ans);
    return 0;
}