常用自定义函数

最新推荐文章于 2024-11-06 19:44:41 发布

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最新推荐文章于 2024-11-06 19:44:41 发布

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原文链接：https://my.oschina.net/mustang/blog/55709

2019独角兽企业重金招聘Python工程师标准>>>

template <class VVType, class T>
void make2DVector(VVType &a, int d, int f, const T &initValue) {
    int i, j;
    a.resize(d);
    for (i = 0; i < d; ++i) {
        a[i].resize(f);
        for (j = 0; j < f; ++j) a[i][j] = initValue;
    }
}

vector<int> primeList;
vector<char> isPrime;

const int NOT_A_PRIME = '\0';
const int IS_A_PRIME = '\1';

int selectPrime(int limit) {
    int k;
    int i;

    primeList.resize(0);
    isPrime.resize(limit + 2);
    for (i = 0; i < isPrime.size(); ++i) isPrime[i] = IS_A_PRIME;
    isPrime[0] = NOT_A_PRIME;
    isPrime[1] = NOT_A_PRIME;

    for (i = 2; i <= limit; ++i) {
        if (isPrime[i]) { primeList.push_back(i); }
        for (k = 0; k < primeList.size(); ++k) {
            int cur = primeList[k] * i;
            if (cur > limit) break;
            isPrime[cur] = NOT_A_PRIME;
            if (i % primeList[k] == 0) break;
        }
    }
}

转载于:https://my.oschina.net/mustang/blog/55709