CSU 1421 Necklace

http://acm.csu.edu.cn/OnlineJudge/problem.php?id=1421

题意：给个项链，上面的元素有不同的颜色，分别进行rotate,flip,swap,paint操作，输出C，CS查询结果。

题解：模拟题……注意是一个环，边界的计数，totate、paint的边界都有坑……还有CS查询存在i==j的情况，要放在<的一类里……基本功不行，敲了3个多小时……

#include <iostream>
#include <cstring>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <string>
#include <vector>
#include <list>
#include <map>
#include <queue>
#include <stack>
#include <bitset>
#include <algorithm>
#include <numeric>
#include <functional>
#include <set>
#include <fstream>

using namespace std;

const int maxn=1010;
int nec[maxn];
int N;

void rotate(int k)
{
    int nec2[maxn];
    for (int i=1; i<=N; i++) {
        if (i+k>N) {
            nec2[(i+k)%N]=nec[i];
        }
        else nec2[i+k]=nec[i];
    }
    for (int i=1; i<=N; i++) {
        nec[i]=nec2[i];
    }
}

void flip()
{
    /*for (int i=1,j=N-1; i<N/2; i++,j--) {
        swap(nec[i], nec[j]);
    }*/
    int co[maxn];
    co[1]=nec[1];
    for (int i=2; i<=N; i++) {
        co[N-i+2]=nec[i];
    }
    for (int i=1; i<=N; i++) {
        nec[i]=co[i];
    }
}

void myswap(int a,int b)
{
    swap(nec[a], nec[b]);
}

void paint(int begin,int end,int colour)
{
    for (int i=begin; i!=end ; i=(i+1)>N?1:i+1) {
        nec[i]=colour;
        //cout<<"n"<<i<<" "<<nec[i]<<endl;
    }
    nec[end]=colour;
}

void parts1()
{
    int parts=0;
    int flag=0;
    for (int i=1; i<=N; i++) {
        if (nec[i]!=flag) {
            parts++;
            flag=nec[i];
        }
    }
    if (parts>1&&nec[1]==nec[N]) {
        parts--;
    }
    printf("%d
",parts);
}

void parts2(int begin,int end)
{
    int parts2=0;
    int flag1=0;
    if (begin>end) {
        for (int i=begin; i<=N; i++) {
            if (nec[i]!=flag1) {
               // cout<<"c"<<i<<" "<<nec[i]<<endl;
                flag1=nec[i];
                parts2++;
            }
        }
        for (int i=1; i<=end; i++) {
            if (nec[i]!=flag1) {
                //cout<<"c"<<i<<" "<<nec[i]<<endl;
                flag1=nec[i];
                parts2++;
            }
        }
    }
    else if(begin<=end){
        int flag2=0;
        for (int i=begin; i<=end; i++) {
            if (nec[i]!=flag2) {
                parts2++;
                flag2=nec[i];
            }
        }
    }
    printf("%d
",parts2);
}

int main()
{
   // freopen("/Users/apple/Desktop/csu 1421/csu 1421/in", "r", stdin);
   // freopen("/Users/apple/Desktop/csu 1421/csu 1421/out", "w", stdout);
    int C,M;
    char o1[5]={'R'};
    char o2[5]={'F'};
    char o3[5]={'S'};
    char o4[5]={'P'};
    char q1[5]={'C'};
    char q2[5]={'C','S'};
    while ((scanf("%d%d",&N,&C))!=EOF) {
        for (int i=1; i<=N; i++) {
            scanf("%d",&nec[i]);
        }
        scanf("%d",&M);
        char s[5];
        for (int i=0; i<M; i++) {
            cin>>s;
            if (strcmp(s, o1)==0) {
                int k;
                cin>>k;
                rotate(k);
            }
            else if (strcmp(s, o2)==0) {
                flip();
            }
            else if (strcmp(s,o3)==0) {
                int i,j;
                cin>>i>>j;
                myswap(i, j);
            }
            else if (strcmp(s, o4)==0) {
                int i,j,x;
                cin>>i>>j>>x;
                paint(i, j,x);
            }
            else if (strcmp(s, q1)==0) {
                parts1();
            }
            else if (strcmp(s, q2)==0) {
                int i,j;
                cin>>i>>j;
                parts2(i,j);
            }
        }
    }
    return 0;
}