代码

#include <cstdio>

int main() {
    int t;
    scanf("%d", &t);
    char outbuf[512]; int outlen = 0;
    while (t--) {
        int L;
        char comp[32];
        scanf("%d %s", &L, comp);
        int expw = 0;
        if (comp[2] == 'n') {
            for (char *p = comp + 4; *p != ')'; ++p) expw = expw * 10 + (*p - '0');
        }
        int stk_var[128], stk_isn[128], stk_isdead[128], stk_contrib[128];
        int top = 0;
        int used[128] = {0};
        int err = 0;
        int dead = 0;
        int cur = 0, maxc = 0;
        for (int i = 0; i < L; ++i) {
            char c;
            scanf(" %c", &c);
            if (c == 'F') {
                char var, xs[16], ys[16];
                scanf(" %c %s %s", &var, xs, ys);
                int vi = (int)var;
                int xnum = (xs[0] >= '0' && xs[0] <= '9');
                int ynum = (ys[0] >= '0' && ys[0] <= '9');
                int this_isdead = 0, this_isn = 0;
                if (!xnum && ynum) this_isdead = 1;
                else if (xnum && !ynum) this_isn = 1;
                else if (xnum && ynum) {
                    int xv = 0, yv = 0;
                    for (char *p = xs; *p; ++p) xv = xv * 10 + (*p - '0');
                    for (char *p = ys; *p; ++p) yv = yv * 10 + (*p - '0');
                    if (xv > yv) this_isdead = 1;
                }
                if (used[vi]) err = 1;
                used[vi] = 1;
                int contributes = this_isn && (dead == 0);
                stk_var[top] = vi;
                stk_isn[top] = this_isn;
                stk_isdead[top] = this_isdead;
                stk_contrib[top] = contributes;
                ++top;
                if (this_isdead) ++dead;
                if (contributes) { ++cur; if (cur > maxc) maxc = cur; }
            } else {
                if (top == 0) err = 1;
                else {
                    --top;
                    used[stk_var[top]] = 0;
                    if (stk_contrib[top]) --cur;
                    if (stk_isdead[top]) --dead;
                }
            }
        }
        if (top != 0) err = 1;
        if (err) { outbuf[outlen++]='E'; outbuf[outlen++]='R'; outbuf[outlen++]='R'; }
        else if (maxc == expw) { outbuf[outlen++]='Y'; outbuf[outlen++]='e'; outbuf[outlen++]='s'; }
        else { outbuf[outlen++]='N'; outbuf[outlen++]='o'; }
        outbuf[outlen++]='\n';
    }
    fwrite(outbuf, 1, outlen, stdout);
    return 0;
}

评测结果