code forces Jeff and Periods
/* * c.cpp * * Created on: 2013-10-7 * Author: wangzhu */ #include<cstdio> #include<iostream> using namespace std; #define NMAX 100010 struct Node { //index:表示两个数直接的距离(-1:表示未开始,0:表示开始:> 0:表示有了距离 //val:记录最后一次的位置 //flag:不符合条件 (0:表示符合条件,1:表示不符合条件) int index, val, flag; } node[NMAX]; int main() { freopen("data.in", "r", stdin); int n,val,k; while(~scanf("%d",&n)) { for(int i = 0;i < NMAX;i++) { node[i].index = -1; node[i].val = 0; node[i].flag = 0; } for(int i = 1;i <= n;i++) { scanf("%d",&val); if(node[val].index > 0) { if(node[val].index != i - node[val].val) { node[val].flag = 1; } } else { if(node[val].val > 0) { node[val].index = i - node[val].val; } else { node[val].index = 0; } } node[val].val = i; } k = 0; for(int i = 0;i < NMAX;i++) { if(node[i].index != -1 && node[i].flag == 0) { k++; } } printf("%d\n",k); for(int i = 0;i < NMAX;i++) { if(node[i].index != -1 && node[i].flag == 0) { printf("%d %d\n",i,node[i].index); } } } return 0; }
超时的方法,如下:
/* * c.cpp * * Created on: 2013-10-7 * Author: wangzhu */ #include<cstdio> #include<iostream> using namespace std; #define NMAX 100010 struct Node { int index, val; } node[NMAX]; int main() { freopen("data.in", "r", stdin); int n,val,k,tempIndex; bool flag; Node tempNode; while(~scanf("%d",&n)) { for(int i = 0;i < n;i++) { scanf("%d",&val); node[i].index = i; node[i].val = val; } for(int i = 0;i < n;i++) { for(int j = 0;j < n - i -1;j++) { if(node[j].val > node[j + 1].val) { tempNode = node[j]; node[j] = node[j+1]; node[j+1] = tempNode; } } } k = 0; flag = true; for(int i = 0;i < n;) { tempNode = node[i]; tempIndex = 0; flag = true; while(i < n && tempNode.val == node[i].val) { if(tempIndex == 0) { tempIndex = node[i].index - tempNode.index; } else { if(tempIndex != node[i].index -tempNode.index) { flag = false; } } tempNode = node[i]; i++; } if(flag) { node[k].val = tempNode.val; node[k].index = tempIndex; k++; } } printf("%d\n",k); for(int i = 0;i <k;i++) { printf("%d %d\n",node[i].val,node[i].index); } } return 0; }