hdu 1496(hash)

/*
*  hash+数学,很好的题 
*  对整数求hash,采用除余法,及线性探测解决冲突 
* 注意:devc++中不能定义全局变量count,它和库函数中的函数名同名了
*/ #include #include #include using namespace std; const int M = 175447; int counts[M]; int result[M]; int temp[101]; int hashInt(int s) { int k = s % M; if (k < 0) k += M; while (counts[k] && result[k]!=s) k = (k + 1) % M; return k; } int solve(int a, int b, int c, int d) { if (a>0&&b>0&&c>0&&d>0 || a<0&&b<0&&c<0&&d<0) return 0; memset(counts, 0, sizeof(counts)); int s, p, i, j; for (i=1; i<101; ++i) { for (j=1; j<101; ++j) { s = a * temp[i] + b * temp[j]; p = hashInt(s); result[p] = s; ++counts[p]; } } int ans = 0; for (i=1; i<101; ++i) { for (j=1; j<101; ++j) { s = -(c * temp[i] + d * temp[j]); p = hashInt(s); ans += counts[p]; } } return ans; } int main() { int a, b, c, d; for (int i=1; i<101; ++i) temp[i] = i * i; while (scanf("%d%d%d%d", &a, &b, &c, &d) != EOF) { int ans = solve(a, b, c, d); printf ("%d\n", ans<<4); } return 0; }

 

转载于:https://www.cnblogs.com/try86/archive/2012/04/09/2439535.html

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