UVa 914 - Jumping Champion

来源：互联网发布：俄罗斯生活知乎编辑：程序博客网时间：2024/06/10 06:22

題目：計算一個區間內，連續素數的差值的眾數，如果有多個或沒有就認為不存在。

分析：數論。直接打表計算素數，然後直接枚舉統計輸出即可。

說明：不要用while(scanf("%d")!=EOF)，會TLE，╮(╯▽╰)╭。

#include <cstring>#include <cstdio>int visit[1000005];int prime[78500];int cut[120];int main(){int count = 0;memset(visit, 0, sizeof(visit));for (int i = 2; i < 1000004; ++ i)if (!visit[i]) {prime[count ++] = i;for (int j = i+i; j < 1000004; j += i)visit[j] = 1;}int n, L, U;scanf("%d",&n);while (n --) {scanf("%d%d",&L,&U);memset(cut, 0, sizeof(cut));for (int i = 0; i < count; ++ i) {if (prime[i+1] > U) break;if (prime[i] >= L && prime[i+1] <= U)cut[prime[i+1]-prime[i]] ++;}int max = 0;for (int i = 1; i < 120; ++ i)if (cut[max] < cut[i])max = i;int count = 0;for (int i = 1; i < 120; ++ i)if (cut[max] == cut[i])count ++;if (max < 1 || count > 1)printf("No jumping champion\n");else printf("The jumping champion is %d\n",max);}return 0;}

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