做了一夜 再也不想敲键盘了..等等再报告 贴出来先 (其实又没人看….)

没有什么任何优化 直接0msAC 真不好意思 XD

#include <cstdio>
#include <cstring>
#include <cmath>
#define MAXNUM 2000

typedef struct pair {
    int v,l;
} Pair;

typedef struct pointer {
    int p,num;
} Pointer;

Pair a[MAXNUM],r[MAXNUM];
int width,prow,rp;
Pointer p2,p5,p8;

void calc();
void set(Pointer *target,int p,int num);
void go(int spit,int steps);
void gop(Pointer *p,int steps);
int pre(Pointer p);
int next(Pointer p);
int spit();;

int main() {
    int i;
    while(1) {
        rp=0;
        scanf("%d",&width);
        if(width==0) {
            printf("0\n");
            return 0;
        }
        for(i=1;;i++) {
            scanf("%d%d",&a[i].v,&a[i].l);
            if(!a[i].v&&!a[i].l)
                break;
        }
        a[0].v=a[i].v=-1;
        a[0].l=a[i].l=width;
        r[0].v=-1;
        r[1].l=0;
        calc();
        printf("%d\n",width);
        for(i=1;;i++) {
            printf("%d %d\n",r[i].v,r[i].l);
            if(!r[i].v&&!r[i].l)
                break;
        }
    }
}

void calc() {
    int i,counter;
    int x,y,z,steps;
    prow=1;
    set(&p2,0,1);
    set(&p5,1,1);
    counter=0;
    for(i=1;counter<=width;i++)
        counter+=a[i].l;
    i--;
    set(&p8,i,width-counter+a[i].l+1);
    while(1) {
        if(a[p5.p].v==-1)
            break;
        x=a[p2.p].l-p2.num;
        y=a[p5.p].l-p5.num;
        z=a[p8.p].l-p8.num;
        steps=x>y?y:x;
        steps=steps>z?z:steps;
        if(steps<3) {
            go(spit(),1);
            continue;
        }                           //可在此处插入判断边界程序
        go(spit(),1);
        go(spit(),steps-1);
    }
    rp++;
    r[rp].v=r[rp].l=0;
}

void set(Pointer *target,int p,int num) {
    target->p=p;
    target->num=num;
}

int spit(){
    int result=0,i=0,temp,x=a[p5.p].v;
    bool top=false,bottom=false;
    if(a[p2.p].v==-1)
        top=true;
    if(a[p8.p].v==-1)
        bottom=true;
    if(prow!=1) {
        if(!top)
            result=(temp=fabs(pre(p2)-x))>result?temp:result;
        result=(temp=fabs(pre(p5)-x))>result?temp:result;
        if(!bottom)
            result=(temp=fabs(pre(p8)-x))>result?temp:result;
    }
    if(prow!=width) {
        if(!top)
            result=(temp=fabs(next(p2)-x))>result?temp:result;
        result=(temp=fabs(next(p5)-x))>result?temp:result;
        if(!bottom)
            result=(temp=fabs(next(p8)-x))>result?temp:result;
    }
    if(!top)
        result=(temp=fabs(a[p2.p].v-x))>result?temp:result;
    if(!bottom)
        result=(temp=fabs(a[p8.p].v-x))>result?temp:result;
    return result;
}

int pre(Pointer p) {
    if(p.num==1)
        return(a[p.p-1].v);
    else
        return(a[p.p].v);
}

int next(Pointer p) {
    if(p.num==a[p.p].l)
        return(a[p.p+1].v);
    else
        return(a[p.p].v);
}

void go(int spit,int steps) {
    if(r[rp].v==spit)
        r[rp].l+=steps;
    else {
        rp++;
        r[rp].v=spit;
        r[rp].l=steps;
    }
    gop(&p2,steps);
    gop(&p5,steps);
    gop(&p8,steps);
    prow=(prow+steps-1)%width+1;
}

void gop(Pointer *p,int steps) {
    p->num+=steps;
    while(p->num>a[p->p].l) {
        p->num-=a[p->p].l;
        p->p++;
    }
}