2020初中暑假训练 第二套

t1切圆 cut

#include<cstdio>
using namespace std;
long long n;
int main(){
    freopen("cut.in","r",stdin);
    freopen("cut.out","w",stdout);
    scanf("%lld",&n);
    printf("%lld",n*(n+1)/2+1);
    return 0;
}

 

 

t2 play

#include<cstdio>
#include<cstring>
using namespace std;
int n,m,xa,ya,xb,yb,l,ans=1;char c[2005][2005],s[5005];bool f;
int dx[]={0,0,-1,1},dy[]={-1,1,0,0};
int go(char a){
    switch(a){
        case 'a':return 0;
        case 'd':return 1;
        case 'w':return 2;
        case 's':return 3;
    }
}
int main(){
    freopen("play.in","r",stdin);
    freopen("play.out","w",stdout);
    scanf("%d%d",&n,&m);
    for(int i=1;i<=n;++i){
        scanf("%s",c[i]+1);
        if(!xa||!xb)
            for(int j=1;j<=m;++j)
                switch(c[i][j]){
                    case 'a':c[xa=i][ya=j]='#';break;
                    case 'b':xb=i;yb=j;break;
                }
    }
    scanf("%s",s);
    l=strlen(s);
    for(int i=0;i<l;++i){
        int x=xa+dx[go(s[i])],y=ya+dy[go(s[i])];
        if(x && x<=n && y && y<=m && c[x][y] != '*'){
            xa=x,ya=y;
            if(x==xb && y==yb) f=1;
            if(c[x][y] != '#') ++ans,c[x][y]='#';
        }
    }
    printf("%d\n",ans);
    f?printf("YES"):printf("NO");
    return 0;
}

 

t3 计蒜客

//栈的基础练习
#include<iostream>
#include<cstdio>
#include<cmath>
#include<cstring>
#include<algorithm>
#include<queue>
#include<stack>
using namespace std;
stack<int> sa; stack<char> st;
int val[505],ans,n;
char s[305];
void init(){
    val['*'] = 2;
    val['/'] = 2;
    val['+'] = 1;
    val['-'] = 1;
}
int main(){
    init();
    scanf("%d%s",&n,s+1);
    int len = strlen(s+1);
    s[0] = '('; s[len+1] = ')';
    for(int i = 0; i <= len+1; i++){
        // cout<<"chu: "<<i<<" "<<s[i]<<endl;
        if(s[i] == '('){
             st.push(s[i]);//如果是左括号，则直接入栈
             // cout<<"fuhao: "<<s[i]<<endl;
        }
        else if(s[i] >= '0' && s[i] <= '9'){
            int tmp = s[i] - '0';
            int j = i;
            while(s[j+1] >= '0' && s[j+1] <= '9'){
                j++;
                tmp = tmp * 10 + s[j] - '0';
            }
            i = j;
            sa.push(tmp);
            // cout<<"i:"<<i<<endl;
        }else{
            while(!st.empty() && val[s[i]] <= val[st.top()]){//如果当前符号<=
                // cout<<"youxianjipanduan: "<<s[i]<<""<<val[s[i]]<<" "<<st.top()<<" "<<val[st.top()]<<endl;
                if(st.top() == '('){//特判：如果栈定是左括号，就不进行计算了
                    if(s[i] == ')')
                        st.pop();
                    break;
                }
                int xa = sa.top(); sa.pop();
                int xb = sa.top(); sa.pop(); int xc = 0;
                char sig = st.top(); st.pop();
                if(sig == '*')
                    xc = xb * xa;
                else if(sig == '/')
                    xc = xb / xa;
                else if(sig == '+')
                    xc = xb + xa;
                else if(sig == '-')
                    xc = xb - xa;
                // cout<<"youxianji: "<<xc<<endl;
                ans = xc;
                sa.push(xc);
            }
            if(s[i] != ')') st.push(s[i]);
            // cout<<"fuhao: "<<s[i]<<endl;
            // if(st.empty()|| val[s[i]] > val[st.top()])
            //     st.push(s[i]);
        }
    }
    // cout<<"end:"<<endl;
    // while(!sa.empty()){
    //     cout<<sa.top()<<endl;
    //     sa.pop();
    // }
    // while(!st.empty()){
    //     cout<<st.top()<<endl;
    //     st.pop();
    // }
    cout<<ans<<endl;
    return 0;
}
// 31+(10-2*3+4)/3
// 31+8/3
//
//1+(17*2+5-13/4)/4-16/2
//10-16/2